Drupal 8 - Add paragraph reference to nodes without one

Drupal 8 - Add paragraph reference to nodes without it already

use Drupal\paragraphs\Entity\Paragraph;

$query = \Drupal::entityQuery('node');

// get all blogs with the flexible content field
$node_ids = $query
    ->condition('status', 1)
    ->condition('type','insight')
    ->exists('field_flexible_content')
    ->execute();

// get a list of nodes with the in-content newsletter form
// already added to flexible content
$node_ids_with_in_content_form_newsletter = [];
foreach($node_ids as $node_id) {
  $node = \Drupal\node\Entity\Node::load($node_id);
  $flexible_paragraphs = $node->get('field_flexible_content')->referencedEntities();
  foreach($flexible_paragraphs as $parag) {
    if($parag->getParagraphType()->id == 'in_content_form') {
      $form_paragraphs = $parag->get('field_form_picker')->referencedEntities();
      foreach($form_paragraphs as $parag2) {
        if($parag2->getParagraphType()->id == 'in_content_form_newsletter') {
          array_push($node_ids_with_in_content_form_newsletter, $node_id);
          break;
        }
      }
    }
  }
}

// remove nodes with in-content newsletter form from list of blog nodes
foreach($node_ids_with_in_content_form_newsletter as $node_id) {
  foreach (array_keys($node_ids) as $key) {
    if ($node_ids[$key] === $node_id)  {
        unset($node_ids[$key]);
    }
  }
}

// print_r("Content with newsletter form already:");
// print_r($node_ids_with_in_content_form_newsletter);
// 
// print_r("Content still needing it:");
// print_r($node_ids);

// the remaining list ($node_ids) are the blog nodes without the
// in-content newsletter form. Add a new in-content newsletter form
// to each of them.
foreach($node_ids as $node_id) {
  $node = \Drupal\node\Entity\Node::load($node_id);

  // create and save in-content newsletter form paragraph
  $subparagraph = Paragraph::create(['type' => 'in_content_form_newsletter']);
  $subparagraph->isNew();
  $subparagraph->save();

  // create in-content form paragraph
  $paragraph = Paragraph::create(['type' => 'in_content_form']);
  $paragraph->isNew();

  // add new in-content newsletter form paragraph to new in-content
  // form paragraph's form-picker field and save the in-content
  // form paragraph.
  $currentparags = $paragraph->get('field_form_picker')->getValue();
  $currentparags[] = array(
    'target_id' => $subparagraph->id(),
    'target_revision_id' => $subparagraph->getRevisionId(),
  );
  $paragraph->set('field_form_picker', $currentparags);
  $paragraph->save();

  // get the current flexible content paragraphs and add the new
  // in-content form paragraph to the node's flexible content.
  $current = $node->get('field_flexible_content')->getValue();
  $current[] = array(
    'target_id' => $paragraph->id(),
    'target_revision_id' => $paragraph->getRevisionId(),
  );
  $node->set('field_flexible_content', $current);

  // save the node
  $node->save();
}