Exclude by missing meta value in WordPress query is not logged in using the Members plugin

gistfile1.txt

add_filter( 'pre_get_posts', 'rrwd_filter_posts' );
function rrwd_filter_posts( $query ) {
  if( !is_user_logged_in() ) {
		
		$meta_query = array(
			array(
				'key' => '_members_access_role',
				'compare' => 'NOT EXISTS'
			)
		);
		
		$query->set( 'meta_query', $meta_query );
		
	}
	return $query;
}