Ordering by meta_value AND date NOT WORKING with wp_query

You have to use the posts_orderby filter to do this at the mo, eg

function wpse159469_posts_orderby( $orderby, $query ) {
    return implode( ' DESC,', explode( ',', str_replace( array(' ASC', ' DESC' ), '', $orderby ) ) ) . ' DESC';
}

then around your query:

add_filter( 'posts_orderby', 'wpse159469_posts_orderby', 10, 2 );
$query = new WP_Query( array( // etc
remove_filter( 'posts_orderby', 'wpse159469_posts_orderby', 10 );