reverted:
--- b/core/modules/text/src/Plugin/Field/FieldType/TextFieldItemList.php
+++ /dev/null
@@ -1,35 +0,0 @@
-<?php
-
-namespace Drupal\text\Plugin\Field\FieldType;
-
-use Drupal\Core\Field\FieldItemList;
-use Drupal\Core\Form\FormStateInterface;
-
-/**
- * Defines an item list class for text fields.
- */
-class TextFieldItemList extends FieldItemList {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function defaultValuesFormValidate(array $element, array &$form, FormStateInterface $form_state) {
-    if ($allowed_formats = $this->getSetting('allowed_formats') && !empty($allowed_formats)) {
-      $field_name = $this->definition->getName();
-      $submitted_values = $form_state->getValue([
-        'default_value_input',
-        $field_name,
-      ]);
-      foreach ($submitted_values as $delta => $value) {
-        if (!in_array($value['format'], $allowed_formats, TRUE)) {
-          $form_state->setErrorByName(
-            "default_value_input][{$field_name}][{$delta}][format",
-            $this->t("The selected text format is not allowed.")
-          );
-        }
-      }
-    }
-    parent::defaultValuesFormValidate($element, $form, $form_state);
-  }
-
-}
diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextItemBase.php
@@ -59,9 +59,14 @@
   public static function calculateDependencies(FieldDefinitionInterface $field_definition) {
     // Add explicitly allowed formats as config dependencies.
     $dependencies = parent::calculateDependencies($field_definition);
-    $format_dependencies = array_map(function (string $format_id) {
-      return 'filter.format.' . $format_id;
-    }, $field_definition->getSetting('allowed_formats'));
+    if (!is_null($field_definition->getSetting('allowed_formats'))) {
+      $format_dependencies = array_map(function (string $format_id) {
+        return 'filter.format.' . $format_id;
+      }, $field_definition->getSetting('allowed_formats'));
+    }
+    else {
+      $format_dependencies = [];
+    }
     $config = $dependencies['config'] ?? [];
     $dependencies['config'] = array_merge($config, $format_dependencies);
     return $dependencies;
diff -u b/core/modules/text/tests/src/Functional/TextFieldTest.php b/core/modules/text/tests/src/Functional/TextFieldTest.php
--- b/core/modules/text/tests/src/Functional/TextFieldTest.php
+++ b/core/modules/text/tests/src/Functional/TextFieldTest.php
@@ -265,10 +265,7 @@
    * Helper function for testTextfieldWidgetsFormatted().
    */
   public function _testTextfieldWidgetsFormatted($field_type, $widget_type) {
-    /** @var \Drupal\Core\Render\RendererInterface $renderer */
-    $renderer = $this->container->get('renderer');
-
-    // Create a field.
+     // Create a field.
     $field_name = mb_strtolower($this->randomMachineName());
     $field_storage = FieldStorageConfig::create([
       'field_name' => $field_name,
reverted:
--- b/core/modules/text/text.install
+++ /dev/null
@@ -1,31 +0,0 @@
-<?php
-
-/**
- * @file
- * Install, update, and uninstall functions for the text module.
- */
-
-use Drupal\text\Plugin\Field\FieldType\TextItemBase;
-use Drupal\Core\Config\Entity\ConfigEntityUpdater;
-use Drupal\field\FieldConfigInterface;
-
-/**
- * Add allowed_formats setting to existing text fields.
- */
-function text_update_9201(&$sandbox) {
-  \Drupal::classResolver(ConfigEntityUpdater::class)
-    ->update($sandbox, 'field_config', function (FieldConfigInterface $field_config) {
-      $class = get_class($field_config);
-      // Deal only with text fields and descendants.
-      if ($class == TextItemBase::class || is_subclass_of($class, TextItemBase::class)) {
-        // Get the existing allowed_formats setting.
-        $allowed_formats = $field_config->get('settings.allowed_formats');
-        if (!is_array($allowed_formats) && empty($allowed_formats)) {
-          // Save default value if existing value not present.
-          $field_config->set('settings.allowed_formats', []);
-        }
-        return TRUE;
-      }
-      return FALSE;
-    });
-}