Allow only certain Gutenberg blocks for specific post types

// functions.php
add_filter( 'allowed_block_types', 'sp_allowed_block_types', 10, 2 );
function sp_allowed_block_types( $allowed_blocks, $post ) {
  $allowed_blocks = array(
    'core/image',
    'core/paragraph',
    'core/heading',
    'core/list'
  );
  if( $post->post_type === 'page' ) {
    $allowed_blocks[] = 'core/shortcode';
  }
  return $allowed_blocks; 
}