Personally, it seems to me like the changes in character appearance are simply due to the new graphics engine being used. The map facelifts are going to be considerably more severe since they're basically ousting the copy/paste redundancy to allow for such large "seamless" maps. But it's not like our characters are also going to have crystals popping out of our pores. (... unless it's an event or enfeeblement or something...)

The need to rehash our appearance is more or less based on the aesthetic preferences of we the players, not some kind of magical face-melting event in the game's story. So I'm just hoping it's an option thrown up there when we log in on a character for the first time after the overhaul.