I really like this idea.
I always found it weird that in all those decades people wouldn't find some way to reclaim the knowledge from prewar days. I mean, yeah, The brotherhood and the institute tend to send their thugs to steal from you if you end up having new technology they want and that could very easily hinder your progress as an group. But I could also see a bunch of random people defiantly learning about those tech in secret, etc. After all, if the brotherhood and the institute want to hoard it for themselves so badly then there must be something to it.
Plus, if you beat both the brotherhood and the institute in the game like I did? I can see scavengers going over the ruins of the brotherhood and the institute and finding all sorts of new tech that they could reverse-engineer for themselves.
Bethesda is kind of stuck in the basic "world has been destroyed and everything is in ruins" premise of post-apocalyptic w/o much thought to the time that's passed since the War. You can see the difference w/Obsidian's handling of the west coast in New Vegas. The NCR and Legion are both fully functional nation-states. Their tech level is not fully pre-War, but they're far from primitive and groups like the Gun Runners are producing fresh high-tech gear rather than just scavenging it. The Commonwealth kind of has an excuse in that the Institute keeps sabotaging any attempts to form an equivalent to the NCR, but still. I mean everybody is still living in scavenged scrap shacks like carpentry is lost technology, despite predating the Industrial Revolution by centuries.