I'm going to try and be as civil as possible so we can all get away from the blatant insults and namecalling, alright? And I'm going to try and clarify so people can stop taking this so damn personally.
Classic WoW was a cultural phenomenon DURING ITS TIME. I do not dispute that! But that time is not now. Right now it's 13 years later, and the context for Vanilla has changed completely, in terms of the community and the technology. The idea that simply releasing a version of WoW that was from 13 years ago is going to magically re-create the "glory" of the game is just false.
What you're describing is a scenario filtered through a dense haze of nostalgia. And I don't disagree that an official release of a vanilla server will be popular for a short while. But that popularity will VERY quickly wear out as the higher standards of today reveal the game for just how bad it really is.
Are some people still going to play it, despite that? Sure. But they're going to be the exception, not the rule.