i don't think it will be the same.
many of the hardcore players from back then has moved on and don't have the time to commit to a second life in wow anymore and it will draw the attention of a lot of fags who only heard about how great vanilla was second hand from boomers who look at it with rose tinted glasses. even people who say they would prefer a lot of the things that differentiates old mmos from new ones have gotten used to instant gratification and convenience in games, so now old is forced to mix with the new who are impatient and only has 10 minutes to run a dungeon but ragequits after 5 because you wiped to trash since no one knows wtf is going on.
i bet the forums will be rampant with "i'm a paying customer so i demand this and that!" too. mmos now are shit but most often it's because of mmo gaymers being fucking retarded and i don't see why it won't happen here as well.