Oh I think I just figured it out, there was apparently a page 1 to this post that I missed:
https://tri.be/support/forums/topic/make-a-specific-calendarcatagory-private/
I just had to updat the code to list the slugs of the cateogires I wanted to make private here in the code, seems to work fine now…
$taxquery = array( ‘taxonomy’ => TribeEvents::TAXONOMY,
‘field’ => ‘slug’,
‘terms’ => array( ‘u12-team-events’, ‘u14-team-events’, ‘u16-team-events’, ‘u18-team-events’, ‘u21-team-events’, ‘adult-team-events’ ),
‘operator’ => ‘NOT IN’ );