That happened not because they wanted to reboot FFXIV, it happened because FFXIV was total and utter shit at launch (probably still is), had a rushed beta, and was just like, beyond not worth playing. Figures that a company that hasn't made a decent single-player game for a decade* wasn't able to translate a shitty formula into a good online game. For the second time.
WoW is still the most popular paid MMO, a total juggernaut in its field, the MMO every other one tries to imitate. Relaunching it would probably only make it fall prey to the same garbage that made TOR and every other WoW wannabe terrible.
They've got an objectively winning formula that, from a monetary standpoint, is literally the best. So, no.
* I do love 1-6 and 9 of Final Fantasy. This generalization does not include remakes or re-releases of the good ones.