In my opinion, Mavericks lobby is fine, their games are fine too, but no one plays it due to the following reasons:
First, there is a quite small amount of players that play those games.
Second, not many players like Basketball, because it is pretty boring game. Also there is their Master Builders version, and there is already one existing and original.
Third, those games are not that popular.
I wouldn't change the whole lobby, I would change the Mineplex system and listen to the community and prioritze on more important things that would make the server stand out.
Oh, back to the question woops, I go a bit off track sometimes.
I would change it back to the old tree, I prefer it tbh. :'D