They could have hired a songwriter/musician(s) to create era sounding tunes that were about the 2065's trends, topics, and issues.
One thing I always found interesting about New Vegas, is that a huge chunk of the music is actually fairly recent, dating to the 90s and 2000s, but is just from obscure artists so nobody really notices the difference.
Lone Star, Let's Ride in to the Sunset Together and In The Shadow of the Valley are all written by a swing band who seem to make most of their money licensing songs for TV shows.
but that also ties into another issue with the Bethesda Fallouts where EVERYTHING has to be prewar, nothing is developed by anyone, they even retconned the Vertibirds to be in active use pre war instead of being prototypes not in active and then completed by the Enclave
I will admit, the idea of the Enclave developing a new type of Aircraft AND Power Armour, while on an oil rig is pretty stupid. Like new tech developing in the Fallout Universe is a good thing but it's like, I'm not fully convinced that they could adequately get all of the raw materials and parts needed to manufacture something so advanced, while having very limited presence on the mainland.
That said, it's a pointless retcon that exists for no reason. I don't really think "I personally found it dumb" is a good reason to rewrite the franchise.
I agree, creating something new would be more worthwhile, but I still think that trying to develop these concepts into something respectful towards the legacy of previous games would be an interesting exercise.
Thing is, my biggest criticism of Fallout 3 isn't lore shit or whatever, but rather that it offers basically nothing original to the franchise. All the major plot elements are basically just rehashes of concepts from 1 and 2, and all the towns are basically one note, with very little complexity. This means that in order to be good/legitimate to my eyes, a Fallout 3 rewrite would have to have so many original ideas and towns, that it would basically at that point become unrecognisable as Fallout 3.
This is going to sound like an exagguration but I think Fallout 3 is so generic, that it's not really worth trying to fix. The only thing that really distinguishes the Capital Wasteland from literally anywhere else in the Fallout setting, is the fact that it's in Washington DC.
A piece of media that's insulting at least has potential to be rewritten because the core ideas are still there. I think it's basically an impossible task to rewrite something this derivative.