This looks good but how would you query the users now ? with get_users ? or with new WP_User_Query ? And like this ?
// WP_User_Query arguments
$args = array (
'who' => 'all',
'tax_query' => array(
array('taxonomy' => 'mytaxonomy',
'field' => 'id',
'terms' => $term_id ) )
);
// The User Query
$user_query = new WP_User_Query( $args );