I believe the Warden is going to utilize Alpha Omega's most interesting and charismatic asset and flip him against us as a major antagonistic.
It would make sense Rushmore could have survived the dark aether implosion at the end of BO4s story, and if the rumors are true that the major threat of this story wants to restore the original multiverse, who is a better character to utilize than only one of two entities in the entire lore who experienced both Ultimus and Primis in one place.
With Rushmore's deep knowledge of the previous world and his direct experience with these crews, this could have a direct link to what motivated the Warden to bring the new version of our old crew to the dark aether in the first place.
It would also create a unique dynamic where, with the Warden's corruption, Rushmore would see our new crew and become antagonistic as he believes they were responsible for his situation, which they technically were. In a way, just like the original warden in Mob/Blood holding the crew in purgatory for the Shadowman, we could see Rushmore take on a very similar role, and with the new map's teasers giving us what looks like a purgatory theme, there's just too many parallels.
We've already seen what the Warden could do with OSCAR using Dean Roth's memories, ripping directly from the IW universe as seen with the cabin in Ashes and the trinket on Astra being directly from Spaceland. And what are the odds the most recent map gave us the original PAP machine? I think we're starting to see more and more elements from the original story as the Warden rips them from hyper intelligent database that is Rushmore.
What are yalls thoughts? I think Rushmore's personality would make him a standout elite enemy, like Uber Klaus but with even more flare and a more interesting set of abilities.