Gutenberg Whitelist

gutenberg-whitelist.php

<?php
/**
 * Plugin Name: Control Gutenberg blocks.
 * Description: 
 * Plugin URI:  https://bueltge.de
 * Version:     1.0.0
 * Author:       
 * Author URI:  
 * Licence:     GPLv2+
 */

// Visible only the listet blocks.
add_filter( 'allowed_block_types', function($allowed_block_types, $post) {
  if ($post->post_type !== 'post') {
    return $allowed_block_types;
  }

  return [
    'core/heading',
    'core/paragraph',
    'core/image'
  ];
}, 10, 2 );