I'm not going to assume that they would bite off their own feet by bringing forth this kind of wank-storm unless the archive seriously really did need to move

You know what? It wouldn't matter if they did. It's their project. This is what you don't seem to be processing. The Yuletide archive ran on astolat's code and the collective time and, frankly, money of the mods as a whole. Subject to some reasonable authorial control over location of stories, if they want to move it to a server hosted by NAMBLA, they can. If they want to close it down, they can. If they want to set it on fire, they can. It belongs to them. Not to fandom-as-a-whole. No matter how popular it is.