add_filter('tiny_mce_before_init','wpb_disable_noopener');
function wpb_disable_noopener( $mceInit ) {
    $mceInit['allow_unsafe_link_target'] = true;
    return $mceInit;
}
add_filter( 'wp_targeted_link_rel', '__return_false', 9999 );
add_action( 'wp_loaded', 'wp_remove_targeted_link_rel_filters' );