Most likely nothing is behind the door, All the ink and conpiracy theories took flight because for some reason it was not revisited until now. You would think mainstream history would have learned and just got out of the way. The extended attempts to block the return have been the main catalyst for all of the conspiracies. Mainstream history and archaeology always get confused with profession investigation and being gatekeepers.
9 years before a return.. I'm surprised we won't find Christ himself behind the door.