I like the idea of talent choices in a general sense, but...I feel like they work in WoW because of a variety of factors that don't really exist in XIV. I suppose the biggest one would be tier/gear sets - in WoW you'll actually alter your current talent choices based around whether or not you have the full T20 set from Tomb of Sargeras, because gearsets in that game amplify certain abilities or resources that can have an impact on your build and rotation. It's not EXACTLY this super liberating perfect freedom scenario, but it does at least give some "if p then q" type variety which wouldn't be present in FFXIV. XIV would basically be, "am I doing a dungeon (AOE) or a raid (single target)? set talent appropriately" and move on.

I guess another factor would be that WoW raid bosses are actually frequently an AOE or two-target (what they call "cleave") scenario, whereas in XIV there might be one token fight every raid tier that is a bunch of trash mobs but no real opportunities for non-single target builds to shine.

And frankly, without big sweeping changes to how this game is designed, tanks and healers are gonna be pigeonholed into taking DPS-boosting talents every time.