Agree!
I didn't use to be a fan of WoW's Beta/PTR because of how spoilery it was, but I still engaged with it solely to test out class changes, and despite feedback being ignored or not (I heard that nowadays they listen more to players, though), it felt a bit more interesting than how it's handled here in XIV.
I don't really expect them to create some sort of "job changes testing environment" like that, but I'd absolutely love if they shared more of what are their ideas beforehand, especially when 8.0 is supposed to bring changes/improvements with more substance.
Based on what we've seen so far for the "Encounter Design Expansion", I'm not especially thrilled for the future of the next one being the "Job Design Expansion". The High End fights in DT are excellent, don't get me wrong, but there's almost no novelty or interesting out-of-the-box elements - it's just their safe formula being executed really well. People are coping with the idea that this is supposed to be reflected only for Dawntrail's patch cycle, but I personally only believe when I see it.