You second query performs an entirely new query and does not have the terms set.
Besides, it’s not as efficient to ‘redo’ the query. Instead, hook into pre_get_posts
and change the order there:
function change_order_for_events( $query ) {
//Check if currenty query is the 'main query' and event type taxonomy being viewed
if ( $query->is_main_query() && is_tax('event_type')) {
$query->set( 'meta_key', '_wr_event_date' );
$query->set( 'orderby', 'meta_value_num' );
$query->set( 'order', 'ASC' );
}
}
add_action( 'pre_get_posts', 'change_order_for_events' );
For bonus points you might want to check that the ‘orderby’ and ‘order’ paramters are not set – that way ordering by date becomes default for events on the event type taxonomy pages but can be overridden if required.
All conditionals are available to you.