NCR I like then and there value
Cesar Legion not big fan of slavey
Enclave is preatty much done maybe some pocket left after what happen on F3.
NCR and Cesar are to far from Boston to have any real impact plus they are in a middle of a war between each other.
even if Ceasar is death ( we dont know since we dont know what is Canon or no for FNV) the NCR wouldnt have easy time dealing with what is left behind. I mean Caesar was just the leader, the Legion will not just give up bc he is death
Maybe not NCR, or Caesar's legion since that's more midwestern and west coast,
But it would be nice to see the water traders (Crimson Caravan) and the Followers of the Apocalypse come back.
Also, seeing two different chapters of the Brotherhood of Steel, reunite, and perhaps go to war against each other would be really interesting.
Midwestern BOS would have been more interesting to see than the East Coast BOS here.