Alpha Omega was nuked after the events of the main EE. Considering the dark aether is a trashpit for all these locations thrown into it over the eras, I could see this nuked version, similar to the original Nuketown, thrust into the ruins of New York City after Richtofen destroyed it and won WW2 for the Reich.
In what was considered the greatest city in America during WW2, it only makes sense there would be a bunker system used to protect its civilians. In real life there is a nuclear fallout bunker below the brooklyn bridge itself, for example. The original camp edward facility was also established in the early 60s, so this would fit with the timeline of a post-WW2 setting as we don't know exactly how long WW2 lasted in this version
We know Richtofen was responsible for the bomb that won this war, so this would tie deeply into Richtofen's history with his own personal traumas as well as radios from civilians or government officials that were experiencing this horrific event first hand.
We could have a version of the Rushmore AI that is not only patriotic af and ties deeply with the values of the United States' greatest city, but one that witnessed the events of the destruction in Alpha Omega and plummeting into the dark aether, thus having direct ties to the primis/ultimus crews.
More on Rushmore, it would be interesting to see him take on a more antagonistic role with a warped perception of our new crew, considering to him they look the same as the ones who were responsible for Camp Edward's destruction in the first place. With the Warden dragging our crew down to this place, it would be a cool twist to see how he utilizes Rushmore to his advantage just as he did creating OSCAR
All in all, I think the original Nuketown and bunker sections of Alpha Omega will be a very small part of a much larger map in a new setting, just like how Nacht was for Die Maschine. Especially with how much smaller Astra is than Ashes, I think we're in for a much bigger DLC experience this time around