Agree this is required.
We have clubs who have their own forums - we would like for moderators to control who sees their forums/groups.
Likewise any 'adult' theme should either have moderator approval of when a user asks to join, or an acknowledgement of an agreement or an age restriction - or perhaps a combination of the two - step 1) agree to something or acknowledge your over 18 and b) get moderator approval to join.
Other groups might have no approval, just a request to join them.
With the new groups set-up in 7.3, I do not see why this should be too hard to do.
