diff --git a/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
index 4cc66ec..2d32c64 100644
--- a/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
+++ b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
@@ -129,7 +129,14 @@ public function defaultValuesFormSubmit(array $element, array &$form, FormStateI
   }
 
   /**
-   * {@inheritdoc}
+   * Removes the items with a specific target id.
+   *
+   * @param int $target_id
+   *   The target id of the item to be removed.
+   *
+   * @return $this
+   *
+   * @todo Add this to EntityReferenceFieldItemListInterface in Drupal 9.0.x.
    */
   public function removeItemsByTargetId($target_id) {
     if (isset($this->list)) {
diff --git a/core/lib/Drupal/Core/Field/EntityReferenceFieldItemListInterface.php b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemListInterface.php
index 807cb7f..4a088bf 100644
--- a/core/lib/Drupal/Core/Field/EntityReferenceFieldItemListInterface.php
+++ b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemListInterface.php
@@ -15,14 +15,4 @@
    */
   public function referencedEntities();
 
-  /**
-   * Removes the items with a specific target id.
-   *
-   * @param int $target_id
-   *   The target id of the item to be removed.
-   *
-   * @return $this
-   */
-  public function removeItemsByTargetId($target_id);
-
 }
diff --git a/core/modules/forum/src/Tests/ForumTest.php b/core/modules/forum/src/Tests/ForumTest.php
index f0f123a..6733f34 100644
--- a/core/modules/forum/src/Tests/ForumTest.php
+++ b/core/modules/forum/src/Tests/ForumTest.php
@@ -433,7 +433,7 @@ function createForum($type, $parent = 0) {
     $parent_tid = $term_entity->parent->target_id;
     $this->assertTrue($parent == $parent_tid, 'The ' . $type . ' is linked to its container');
 
-    $forum = $this->container->get('entity.manager')->getStorage('taxonomy_term')->load($term_entity->id());
+    $forum = Term::load($term_entity->id());
     $this->assertEqual(($type == 'forum container'), (bool) $forum->forum_container->value);
     return $term;
   }
diff --git a/core/modules/taxonomy/src/Entity/Term.php b/core/modules/taxonomy/src/Entity/Term.php
index cfddf51..8cbfdda 100644
--- a/core/modules/taxonomy/src/Entity/Term.php
+++ b/core/modules/taxonomy/src/Entity/Term.php
@@ -7,6 +7,7 @@
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\taxonomy\TermHierarchyInterface;
 use Drupal\taxonomy\TermInterface;
 
 /**
@@ -50,7 +51,7 @@
  *   permission_granularity = "bundle"
  * )
  */
-class Term extends ContentEntityBase implements TermInterface {
+class Term extends ContentEntityBase implements TermInterface, TermHierarchyInterface {
 
   use EntityChangedTrait;
 
diff --git a/core/modules/taxonomy/src/Entity/Vocabulary.php b/core/modules/taxonomy/src/Entity/Vocabulary.php
index c453475..120fee9 100644
--- a/core/modules/taxonomy/src/Entity/Vocabulary.php
+++ b/core/modules/taxonomy/src/Entity/Vocabulary.php
@@ -173,7 +173,15 @@ public static function postDelete(EntityStorageInterface $storage, array $entiti
   }
 
   /**
-   * {@inheritdoc}
+   * Gets top-level term IDs of vocabularies.
+   *
+   * @param array $vids
+   *   Array of vocabulary IDs.
+   *
+   * @return array
+   *   Array of top-level term IDs.
+   *
+   * @todo Add this to \Drupal\taxonomy\VocabularyInterface in Drupal 9.0.x.
    */
   public static function getTopLevelTids($vids) {
     $tids = \Drupal::entityQuery('taxonomy_term')
diff --git a/core/modules/taxonomy/src/TermHierarchyInterface.php b/core/modules/taxonomy/src/TermHierarchyInterface.php
new file mode 100644
index 0000000..98f3054
--- /dev/null
+++ b/core/modules/taxonomy/src/TermHierarchyInterface.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace Drupal\taxonomy;
+
+/**
+ * Provides an interface for handling taxonomy term hierarchy.
+ *
+ * @todo Merge this into \Drupal\taxonomy\TermInterface in Drupal 9.0.x.
+ */
+interface TermHierarchyInterface {
+
+  /**
+   * Returns a list of parents of this term.
+   *
+   * @return \Drupal\Core\Field\EntityReferenceFieldItemListInterface
+   *   A list of references to parents taxonomy terms. If this term has a <root>
+   *   parent that item is keyed with 0 and have NULL as value.
+   */
+  public function getParents();
+
+  /**
+   * Returns all ancestors of this term.
+   *
+   * @return \Drupal\taxonomy\TermInterface[]
+   *   A list of ancestor taxonomy term entities keyed by term id.
+   */
+  public function getAncestors();
+
+  /**
+   * Returns all children terms of this term.
+   *
+   * @param string $vid
+   *   An optional vocabulary ID to restrict the child search.
+   *
+   * @return \Drupal\taxonomy\TermInterface[]
+   *   A list of children taxonomy term entities keyed by term id.
+   */
+  public function getChildren($vid = NULL);
+
+}
diff --git a/core/modules/taxonomy/src/TermInterface.php b/core/modules/taxonomy/src/TermInterface.php
index 4607a46..68da4b6 100644
--- a/core/modules/taxonomy/src/TermInterface.php
+++ b/core/modules/taxonomy/src/TermInterface.php
@@ -7,6 +7,8 @@
 
 /**
  * Provides an interface defining a taxonomy term entity.
+ *
+ * @todo Merge here \Drupal\taxonomy\TermHierarchyInterface in Drupal 9.0.x.
  */
 interface TermInterface extends ContentEntityInterface, EntityChangedInterface {
 
@@ -90,32 +92,4 @@ public function setWeight($weight);
    */
   public function getVocabularyId();
 
-  /**
-   * Returns a list of parents of this term.
-   *
-   * @return \Drupal\Core\Field\EntityReferenceFieldItemListInterface
-   *   A list of references to parents taxonomy terms. If this term has a <root>
-   *   parent that item is keyed with 0 and have NULL as value.
-   */
-  public function getParents();
-
-  /**
-   * Returns all ancestors of this term.
-   *
-   * @return \Drupal\taxonomy\TermInterface[]
-   *   A list of ancestor taxonomy term entities keyed by term id.
-   */
-  public function getAncestors();
-
-  /**
-   * Returns all children terms of this term.
-   *
-   * @param string $vid
-   *   An optional vocabulary ID to restrict the child search.
-   *
-   * @return \Drupal\taxonomy\TermInterface[]
-   *   A list of children taxonomy term entities keyed by term id.
-   */
-  public function getChildren($vid = NULL);
-
 }
diff --git a/core/modules/taxonomy/src/TermStorageInterface.php b/core/modules/taxonomy/src/TermStorageInterface.php
index d6213a0..4a4f396 100644
--- a/core/modules/taxonomy/src/TermStorageInterface.php
+++ b/core/modules/taxonomy/src/TermStorageInterface.php
@@ -16,7 +16,8 @@
    * @param array $tids
    *   Array of terms that need to be removed from hierarchy.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0.
+   * @todo Remove this method in Drupal 9.0.x. Now the parent references are
+   *   automatically cleared when deleting a taxonomy term.
    */
   public function deleteTermHierarchy($tids);
 
@@ -26,7 +27,8 @@ public function deleteTermHierarchy($tids);
    * @param \Drupal\Core\Entity\EntityInterface $term
    *   Term entity that needs to be added to term hierarchy information.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0.
+   * @todo remove this method Drupal 9.0.x. Now the parent references are
+   *   automatically updates when when a taxonomy term is added/updated.
    */
   public function updateTermHierarchy(EntityInterface $term);
 
@@ -39,7 +41,7 @@ public function updateTermHierarchy(EntityInterface $term);
    * @return \Drupal\taxonomy\TermInterface[]
    *   An array of term objects which are the parents of the term $tid.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0. Use
+   * @deprecated in Drupal 8.2.x, will be removed in Drupal 9.0.0. Use
    *   \Drupal\taxonomy\Entity\Term::load($tid)->getParents() instead.
    */
   public function loadParents($tid);
@@ -53,7 +55,7 @@ public function loadParents($tid);
    * @return \Drupal\taxonomy\TermInterface[]
    *   An array of term objects which are the ancestors of the term $tid.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0. Use
+   * @deprecated in Drupal 8.2.x, will be removed in Drupal 9.0.0. Use
    *   \Drupal\taxonomy\Entity\Term::load($tid)->getAncestors() instead.
    */
   public function loadAllParents($tid);
@@ -69,7 +71,7 @@ public function loadAllParents($tid);
    * @return \Drupal\taxonomy\TermInterface[]
    *   An array of term objects that are the children of the term $tid.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0. Use
+   * @deprecated in Drupal 8.2.x, will be removed in Drupal 9.0.0. Use
    *   \Drupal\taxonomy\Entity\Term::load($tid)->getChildren($vid) instead.
    */
   public function loadChildren($tid, $vid = NULL);
diff --git a/core/modules/taxonomy/src/TermViewsData.php b/core/modules/taxonomy/src/TermViewsData.php
index 7854b2a..d9c9fb1 100644
--- a/core/modules/taxonomy/src/TermViewsData.php
+++ b/core/modules/taxonomy/src/TermViewsData.php
@@ -261,4 +261,4 @@ public function getViewsData() {
     return $data;
   }
 
-  }
+}
diff --git a/core/modules/taxonomy/src/Tests/Update/TaxonomyUpdateTest.php b/core/modules/taxonomy/src/Tests/Update/TaxonomyUpdateTest.php
index a5ba473..866fa07 100644
--- a/core/modules/taxonomy/src/Tests/Update/TaxonomyUpdateTest.php
+++ b/core/modules/taxonomy/src/Tests/Update/TaxonomyUpdateTest.php
@@ -1,10 +1,5 @@
 <?php
 
-/**
- * @file
- * Contains \Drupal\taxonomy\Tests\Update\TaxonomyUpdateTest.
- */
-
 namespace Drupal\taxonomy\Tests\Update;
 
 use Drupal\Component\Serialization\Yaml;
@@ -25,20 +20,13 @@ class TaxonomyUpdateTest extends UpdatePathTestBase {
   protected $profile = 'standard';
 
   /**
-   * The databse connection.
+   * The database connection.
    *
    * @var \Drupal\Core\Database\Connection
    */
   protected $db;
 
   /**
-   * The config factory service.
-   *
-   * @var \Drupal\Core\Config\ConfigFactoryInterface
-   */
-  protected $configFactory;
-
-  /**
    * {@inheritdoc}
    */
   public function setDatabaseDumpFiles() {
@@ -53,15 +41,15 @@ public function setDatabaseDumpFiles() {
   protected function setUp() {
     parent::setUp();
     $this->db = $this->container->get('database');
-    $this->configFactory = $this->container->get('config.factory');
   }
 
   /**
-   * Tests taxonomy_update_8001().
+   * Tests taxonomy term parents update.
    *
    * @see taxonomy_update_8001()
+   * @see taxonomy_post_update_parents()
    */
-  public function testTaxonomyUpdate8001() {
+  public function testTaxonomyUpdateParents() {
     $tids = $this->createTerms();
     $vid = $this->createView();
 
@@ -88,7 +76,7 @@ public function testTaxonomyUpdate8001() {
 
     // Test if the view has been converted to use {taxonomy_term__parent} table
     // instead of {taxonomy_term_hierarchy}.
-    $view = $this->configFactory->get("views.view.$vid");
+    $view = $this->config("views.view.$vid");
     $path = 'display.default.display_options.relationships.parent.table';
     $this->assertIdentical($view->get($path), 'taxonomy_term__parent');
 
@@ -97,7 +85,7 @@ public function testTaxonomyUpdate8001() {
   }
 
   /**
-   * Create some terms on a very low level, bypassing the API.
+   * Creates some terms on a very low level, bypassing the API.
    *
    * @return array
    *   A list of created term IDs.
@@ -147,12 +135,16 @@ protected function createTerms() {
   protected function createView() {
     $vid = Unicode::strtolower($this->randomMachineName());
     $file = __DIR__ . '/../../../tests/modules/taxonomy_test_views/test_views/views.view.test_taxonomy_parent.yml';
-
-    $this->configFactory->getEditable("views.view.$vid")
-      ->setData(Yaml::decode(file_get_contents($file)))
-      // Revert the change done in taxonomy_update_8001().
-      ->set('display.default.display_options.relationships.parent.table', 'taxonomy_term_hierarchy')
-      ->save();
+    $config = Yaml::decode(file_get_contents($file));
+
+    $this->container->get('database')->insert('config')
+      ->fields(['collection', 'name', 'data'])
+      ->values([
+        'collection' => '',
+        'name' => "views.view.$vid",
+        'data' => serialize($config),
+      ])
+      ->execute();
 
     return $vid;
   }
diff --git a/core/modules/taxonomy/src/VocabularyInterface.php b/core/modules/taxonomy/src/VocabularyInterface.php
index 9e6f9f7..ff52bec 100644
--- a/core/modules/taxonomy/src/VocabularyInterface.php
+++ b/core/modules/taxonomy/src/VocabularyInterface.php
@@ -39,15 +39,4 @@ public function setHierarchy($hierarchy);
    */
   public function getDescription();
 
-  /**
-   * Gets top-level term IDs of vocabularies.
-   *
-   * @param array $vids
-   *   Array of vocabulary IDs.
-   *
-   * @return array
-   *   Array of top-level term IDs.
-   */
-  public static function getTopLevelTids($vids);
-
 }
diff --git a/core/modules/taxonomy/src/VocabularyStorageInterface.php b/core/modules/taxonomy/src/VocabularyStorageInterface.php
index d5b6a61..3549ee0 100644
--- a/core/modules/taxonomy/src/VocabularyStorageInterface.php
+++ b/core/modules/taxonomy/src/VocabularyStorageInterface.php
@@ -18,7 +18,7 @@
    * @return array
    *   Array of top-level term IDs.
    *
-   * @deprecated in Drupal 8.0.x, will be removed before Drupal 8.1.0. Use
+   * @deprecated in Drupal 8.2.x, will be removed in Drupal 9.0.x Use
    *   \Drupal\taxonomy\Entity\Vocabulary::getTopLevelTids($vids) instead.
    */
   public function getToplevelTids($vids);
diff --git a/core/modules/taxonomy/taxonomy.install b/core/modules/taxonomy/taxonomy.install
index 2369dad..9616467 100644
--- a/core/modules/taxonomy/taxonomy.install
+++ b/core/modules/taxonomy/taxonomy.install
@@ -9,78 +9,28 @@
  * Convert the custom taxonomy term hierarchy storage to a default storage.
  */
 function taxonomy_update_8001(&$sandbox = NULL) {
-  $database = \Drupal::database();
-
-  if (!isset($sandbox['current'])) {
-    // Update entity definition.
-    $manager = \Drupal::entityDefinitionUpdateManager();
-    /** @var \Drupal\Core\Field\BaseFieldDefinition $definition */
-    $definition = $manager->getFieldStorageDefinition('parent', 'taxonomy_term');
-    $definition->setCustomStorage(FALSE);
-    $manager->updateFieldStorageDefinition($definition);
-
-    // Set batch ops sandbox.
-    $sandbox['current'] = 0;
-    $sandbox['max'] = $database->select('taxonomy_term_hierarchy')
-      ->countQuery()
-      ->execute()
-      ->fetchField();
-  }
-
-  // Save the hierarchy.
-  $select = $database->select('taxonomy_term_hierarchy', 'h');
-  $select->join('taxonomy_term_data', 'd', 'h.tid = d.tid');
-  $hierarchy = $select
-    ->fields('h', ['tid', 'parent'])
-    ->fields('d', ['vid', 'langcode'])
-    ->range($sandbox['current'], $sandbox['current'] + 100)
-    ->execute()
-    ->fetchAll();
-
-  // Restore data.
-  $insert = $database->insert('taxonomy_term__parent')
-    ->fields(['bundle', 'entity_id', 'revision_id', 'langcode', 'delta', 'parent_target_id']);
-  $tid = -1;
-  foreach ($hierarchy as $row) {
-    if ($row->tid !== $tid) {
-      $delta = 0;
-      $tid = $row->tid;
-    }
-    $insert->values([
-      'bundle' => $row->vid,
-      'entity_id' => $row->tid,
-      'revision_id' => $row->tid,
-      'langcode' => $row->langcode,
-      'delta' => $delta,
-      'parent_target_id' => $row->parent,
-    ]);
-    $delta++;
-    $sandbox['current']++;
-  }
-  $insert->execute();
-
-  $sandbox['#finished'] = empty($sandbox['max']) ? 1 : ($sandbox['current'] / $sandbox['max']);
-
-  if ($sandbox['#finished'] >= 1) {
-    $factory = \Drupal::configFactory();
-    // Update views with a low level API.
-    foreach ($factory->listAll('views.view.') as $id) {
-      $view = $factory->getEditable($id);
-      $changed = FALSE;
-      foreach ($view->get('display') as $display_id => &$display) {
-        $path = "display.$display_id.display_options.relationships.parent.table";
-        if (!empty($table = $view->get($path)) && $table == 'taxonomy_term_hierarchy') {
-          $view->set($path, 'taxonomy_term__parent');
-          $changed = TRUE;
-        }
-      }
-      if ($changed) {
-        $view->save(TRUE);
+  // Update entity definition.
+  $manager = \Drupal::entityDefinitionUpdateManager();
+  /** @var \Drupal\Core\Field\BaseFieldDefinition $definition */
+  $definition = $manager->getFieldStorageDefinition('parent', 'taxonomy_term');
+  $definition->setCustomStorage(FALSE);
+  $manager->updateFieldStorageDefinition($definition);
+
+  $factory = \Drupal::configFactory();
+  // Update views with a low level API.
+  foreach ($factory->listAll('views.view.') as $id) {
+    $view = $factory->getEditable($id);
+    $changed = FALSE;
+    foreach ($view->get('display') as $display_id => &$display) {
+      $path = "display.$display_id.display_options.relationships.parent.table";
+      if (!empty($table = $view->get($path)) && $table == 'taxonomy_term_hierarchy') {
+        $view->set($path, 'taxonomy_term__parent');
+        $changed = TRUE;
       }
     }
-
-    // Drop the legacy table.
-    $database->schema()->dropTable('taxonomy_term_hierarchy');
-    return t('Taxonomy term hierarchy converted.');
+    if ($changed) {
+      $view->save(TRUE);
+    }
   }
+
 }
diff --git a/core/modules/taxonomy/taxonomy.post_update.php b/core/modules/taxonomy/taxonomy.post_update.php
new file mode 100644
index 0000000..018960d
--- /dev/null
+++ b/core/modules/taxonomy/taxonomy.post_update.php
@@ -0,0 +1,72 @@
+<?php
+
+/**
+ * @file
+ * Post update functions for Taxonomy.
+ */
+
+/**
+ * @addtogroup updates-8.2.x
+ * @{
+ */
+
+/**
+ * Copies hierarchy from {taxonomy_term_hierarchy} to {taxonomy_term__parent}.
+ */
+function taxonomy_post_update_parents(&$sandbox) {
+  $database = \Drupal::database();
+
+  if (!isset($sandbox['current'])) {
+    // Set batch ops sandbox.
+    $sandbox['current'] = 0;
+    $sandbox['max'] = $database->select('taxonomy_term_hierarchy')
+      ->countQuery()
+      ->execute()
+      ->fetchField();
+  }
+
+  // Save the hierarchy.
+  $select = $database->select('taxonomy_term_hierarchy', 'h');
+  $select->join('taxonomy_term_data', 'd', 'h.tid = d.tid');
+  $hierarchy = $select
+    ->fields('h', ['tid', 'parent'])
+    ->fields('d', ['vid', 'langcode'])
+    ->range($sandbox['current'], $sandbox['current'] + 100)
+    ->execute()
+    ->fetchAll();
+
+  // Restore data.
+  $insert = $database->insert('taxonomy_term__parent')
+    ->fields(['bundle', 'entity_id', 'revision_id', 'langcode', 'delta', 'parent_target_id']);
+  $tid = -1;
+  foreach ($hierarchy as $row) {
+    if ($row->tid !== $tid) {
+      $delta = 0;
+      $tid = $row->tid;
+    }
+    $insert->values([
+      'bundle' => $row->vid,
+      'entity_id' => $row->tid,
+      'revision_id' => $row->tid,
+      'langcode' => $row->langcode,
+      'delta' => $delta,
+      'parent_target_id' => $row->parent,
+    ]);
+    $delta++;
+    $sandbox['current']++;
+  }
+  $insert->execute();
+
+  $sandbox['#finished'] = empty($sandbox['max']) ? 1 : ($sandbox['current'] / $sandbox['max']);
+
+  if ($sandbox['#finished'] >= 1) {
+    // Drop the legacy table.
+    $database->schema()->dropTable('taxonomy_term_hierarchy');
+    return t('Taxonomy term hierarchy converted.');
+  }
+
+}
+
+/**
+ * @} End of "addtogroup updates-8.2.x".
+ */