If it's client side changes (only you can see) I can see it happening officially, since I don't think seeing a bunch of reindeer beating on bosses and world HNMs visually appealing lol (since we already can do this for the most part and it just looks silly xD), but if it's for everyone to see, maybe they'll keep it within confines of your class/job -- For example mages can only visually swap to other mage line gear that isn't class/job restricted as you said.