Change, Remove, Add.

[Alahra]

You can change, remove and add a feature/event/anything. But you do need to justify your answer to some extent. Go.

Change: I'd make the "split" zones (East Shroud, Central Shroud, etc.) whole again.

Remove: Flight. I've long been an opponent of flight in fantasy MMOs, and while FFXIV does a better job with implementation of it compared to the most immediate comparison (WoW), I liked the Heavensward zones best when I couldn't fly, as they now feel no larger than the ARR zones in practice despite being massively bigger.

Add: More gearsets at the highest item level for each raid tier (so, to use current item levels, I'd add at least two more i210 sets for stat variety and also glamour potential).