`nav_menu_meta_box_object` filter doesn't work on taxonomies

[papazetis]

I am trying to remove the pagination on main category taxonomy but it doesn't work

<?php
function disable_pagination_in_category_meta_box( $post_type ) {
    if ( 'category' == $post_type->name ) {
        $post_type->_default_query['number'] = -1;
    }
   return $post_type;
}
add_filter( 'nav_menu_meta_box_object', 'disable_pagination_in_category_meta_box', 9 );

Think it's bug but not sure