Unless they are dropping a patch for all the games they already published, when something is called Aeris, it is going to be called Aeris. It does not matter if there are new editions, better translations, or whatnot; your first introduction is going to be the one to leave the strongest impression. So while, yeah, Aerith/Libra/whatever is more correct according to some nerd with an Ultimania (or a nerd who wrote an Ultimania), a certain Square-Enix done smurfed up the first time around when they should have gotten it right.