diff --git a/core/modules/taxonomy/src/TermStorage.php b/core/modules/taxonomy/src/TermStorage.php
index 5d1332a44777609b0c52c458e4bbf70c9a6e6fdf..c01ae66d3adbf1624f1b7f49d48ae80d3815795b 100644
--- a/core/modules/taxonomy/src/TermStorage.php
+++ b/core/modules/taxonomy/src/TermStorage.php
@@ -91,12 +91,16 @@ public function resetCache(array $ids = NULL) {
   /**
    * {@inheritdoc}
    */
-  public function deleteTermHierarchy($tids) {}
+  public function deleteTermHierarchy($tids) {
+    @trigger_error(__METHOD__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. It is a no-op since 8.6.0. Parent references are automatically cleared when deleting a taxonomy term. See https://www.drupal.org/node/2936675', E_USER_DEPRECATED);
+  }
 
   /**
    * {@inheritdoc}
    */
-  public function updateTermHierarchy(EntityInterface $term) {}
+  public function updateTermHierarchy(EntityInterface $term) {
+    @trigger_error(__METHOD__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. It is a no-op since 8.6.0. Parent references are automatically updated when updating a taxonomy term. See https://www.drupal.org/node/2936675', E_USER_DEPRECATED);
+  }
 
   /**
    * {@inheritdoc}
diff --git a/core/modules/taxonomy/src/TermStorageInterface.php b/core/modules/taxonomy/src/TermStorageInterface.php
index 29401868d782aa9dfbffe0e9a4681d710673aacc..41d521156aba0dd8fe9466d166725c09d9145513 100644
--- a/core/modules/taxonomy/src/TermStorageInterface.php
+++ b/core/modules/taxonomy/src/TermStorageInterface.php
@@ -16,9 +16,10 @@ interface TermStorageInterface extends ContentEntityStorageInterface {
    * @param array $tids
    *   Array of terms that need to be removed from hierarchy.
    *
-   * @todo Remove this method in Drupal 9.0.x. Now the parent references are
-   *   automatically cleared when deleting a taxonomy term.
-   *   https://www.drupal.org/node/2785693
+   * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Parent
+   *   references are automatically cleared when deleting a taxonomy term.
+   *
+   * @see https://www.drupal.org/node/2936675
    */
   public function deleteTermHierarchy($tids);
 
@@ -28,9 +29,10 @@ public function deleteTermHierarchy($tids);
    * @param \Drupal\Core\Entity\EntityInterface $term
    *   Term entity that needs to be added to term hierarchy information.
    *
-   * @todo remove this method Drupal 9.0.x. Now the parent references are
-   *   automatically updates when a taxonomy term is added/updated.
-   *   https://www.drupal.org/node/2785693
+   * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Parent
+   *   references are automatically updated when updating a taxonomy term.
+   *
+   * @see https://www.drupal.org/node/2936675
    */
   public function updateTermHierarchy(EntityInterface $term);
 
diff --git a/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
index 29e43b72bf56f8ac7e3f0811748c0d08f0f96024..820924bfeb8435a37fe4c9056d12e013cd0a449c 100644
--- a/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
+++ b/core/modules/taxonomy/tests/src/Kernel/TermKernelTest.php
@@ -168,4 +168,32 @@ public function testTermPreview() {
     $this->assertNotEmpty(trim($rendered), 'Term is able to be rendered.');
   }
 
+  /**
+   * @covers \Drupal\taxonomy\TermStorage::deleteTermHierarchy
+   * @group legacy
+   */
+  public function testDeleteTermHierarchyDeprecation(): void {
+    $vocabulary = $this->createVocabulary();
+    $term = $this->createTerm($vocabulary);
+
+    /** @var \Drupal\taxonomy\TermStorageInterface $storage */
+    $storage = \Drupal::entityTypeManager()->getStorage('taxonomy_term');
+    $this->expectDeprecation('Drupal\taxonomy\TermStorage::deleteTermHierarchy() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. It is a no-op since 8.6.0. Parent references are automatically cleared when deleting a taxonomy term. See https://www.drupal.org/node/2936675');
+    $storage->deleteTermHierarchy([$term->tid]);
+  }
+
+  /**
+   * @covers \Drupal\taxonomy\TermStorage::updateTermHierarchy
+   * @group legacy
+   */
+  public function testUpdateTermHierarchyDeprecation(): void {
+    $vocabulary = $this->createVocabulary();
+    $term = $this->createTerm($vocabulary);
+
+    /** @var \Drupal\taxonomy\TermStorageInterface $storage */
+    $storage = \Drupal::entityTypeManager()->getStorage('taxonomy_term');
+    $this->expectDeprecation('Drupal\taxonomy\TermStorage::updateTermHierarchy() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. It is a no-op since 8.6.0. Parent references are automatically updated when updating a taxonomy term. See https://www.drupal.org/node/2936675');
+    $storage->updateTermHierarchy($term);
+  }
+
 }