Are we ever going to see the unmade things from GMT return?

Okay, so, I’ve been (once again) browsing the GMT Trello for fun and saw some things I would love in TU, and I was curious if they would come to fruition. There’s plenty of things like Rhythm games, Boss Battles (like duels, but I assume PvE.), more Bar functionality, and a whole slew of other stuff. I was wondering if any of it was planned to return, and if so, what?