So Final Fantasy 14? I mean not really the same but in the sense of a reboot that's kinda what they did. I wouldn't mind it if they were going to make a WoW 2, otherwise doing it as an expansion would probably be a bad move. People are very attached to their characters that they've been playing for, in some cases, over a decade.
If they ever decide to make a new world of warcraft I'd be all for it. Otherwise, bad idea.