comment_user_cancel

comment_user_cancel($edit, $account, $method)

function comment_user_cancel($edit, $account, $method) {
  switch ($method) {
    case 'user_cancel_block_unpublish':
      $comments = entity_load_multiple_by_properties('comment', array('uid' => $account->id()));
      foreach ($comments as $comment) {
        $comment->setPublished(CommentInterface::NOT_PUBLISHED);
        $comment->save();
      }
      break;

    case 'user_cancel_reassign':
      /** @var \Drupal\comment\CommentInterface[] $comments */
      $comments = entity_load_multiple_by_properties('comment', array('uid' => $account->id()));
      foreach ($comments as $comment) {
        $comment->setOwnerId(0);
        $comment->setAuthorName(\Drupal::config('user.settings')->get('anonymous'));
        $comment->save();
      }
      break;
  }
}