Sounds like an idea I can get behind to add a bit of depth to this game (and maybe make it feel more like an RPG)
But I can see players demanding you have certain abilities and wanting you to get those before going into a raid and such because of "muh meta" same deal with why I can't see a traditional blue mage in this game working.
Either way to be honest, I'd like them to take a risk and implement this next expansion I guess. I know next to nothing about game design if it doesn't work out because of player behavior they can always patch it out can't they?
and go back to the boring same old same old