Error thrown when $form_state used as array

I added a name form field to a custom form and am seeing this error.

Error: Cannot use object of type Drupal\Core\Form\FormState as array in name_element_expand() (line 245 of web/modules/contrib/name/name.module) #0 [internal function]: name_element_expand(Array, Object(Drupal\Core\Form\FormState), Array)   admin (1)   Error

The error comes from this code:

/**
 * The #process callback to create the element.
 */
  function name_element_expand($element, &$form_state, $complete_form) {
  /**
   * @var \Drupal\Core\Language\Language $language
   */
  $language = Drupal::languageManager()->getCurrentLanguage();

  $element['#tree'] = TRUE;
  if (empty($element['#value'])) {
    $element['#value'] = array();
  }
  $parts = _name_translations();
  $components = $element['#components'];
  $min_components = (array) $element['#minimum_components'];
  if (empty($element['#field'])) {
    $element['#field'] = isset($form_state['field']) ? $form_state['field'] : NULL;
  }

Specifically this line:

$element['#field'] = isset($form_state['field']) ? $form_state['field'] : NULL;

I'm happy to supply a patch, but I'm not 100% sure what this check does and if it is needed. I am able to comment the line out and the module seems to work fine. So perhaps someone else can weigh in. I am going to post a patch that simply disables this for now to unblock myself while we sort out if this is truly needed in D8 and how to recreate the logic if it is.