First of all, the show is very good. I’m extremely impressed with how remarkably “Fallout” the world is and how so very good every single visual is. It really IS real-world Fallout brought to life. From the sets, to the costumes, to the set design… every tiny minuscule detail is perfect! The dialogue, the tone, even the weird sense of dark humor; it’s all there. And the trailers hid a lot, which I’m so grateful for!
But it feels like the narrative of a full-on Fallout game (which, I suppose, it should). It takes place (minor spoilers) in LA, about 10 years after Fallout 4. From what I can tell so far, it’s probably the narrative they would have used for FO5. It’s very good, and would have made for a spectacular game I would have spent another 13,000 hours paying over the better part of a decade, but I reeeaaally wish we could have gotten FO5 instead. Or, ya know, also.
I doubt it is the narrative that would have been fallout 5. Fallout 1 and 2 were developed by black isle studios in Irvine california. They chose to set the game in a post apocalyptic version of the local area. When bethesda purchased the IP and made their own version it was set in capital, literally where their offices are located.
The next west coast fallout, new vegas, was developed by obsidian, also based in Irvine.
Both fallout 4 and 76 were both east coast games based on locations pretty close to the studio that made it.
From the entire history of the series, Fallout has been set near to the studio that made it. Which is why I highly doubt the script was based on the notes of bethesda’s next fallout.
Bethesda and Todd Howard worked very closely with the producers of the series, approving everything along the way.
Edit: edited for clarity.