Yeah, I thought that too, but turns out they just changed the URL. Weird choice for the old URL to throw a 404 error instead of redirecting to the new domain.
Gone are the days when guys like @Mike Tougeron worked there. IIRC, back in the XF 1.0 days, he's the one that migrated their huge forum to Xenforo from their old proprietary forum software. We (TheForce.net) were also hosted by IGN back then and Mike did our Xenforo migration as well.