Being the lead Fallout writer for Bethesda is not exactly something for someone to brag about, Fallout 3, 4 and 76 are all examples of generally mediocre writing at best, there is a reason that New Vegas is considered better then any of the Bethesda developed games although I'll admit to still enjoying FO3 and 4 despite their flaws.
But if that is his role then he does have authority to speak on this topic, so I'll accept that as the timeline and just consider the show as having screwed it up. That said, that still doesn't explain what happened to the NCR at The Hub, or in Nevada and Oregon, the organization was literally too big to "decline" to the level it is in the show, especially just from one nuke going off. Also the TV show is still incoherent trash, but that is much less important to me then the game continuity.
If the show is going to use the NCR, they can't just claim that it was a group from one random city that apparently collapsed after one nuke when those are both absolutely incorrect. They either need to acknowledge that they're only talking about the (relative to them) local NCR, or not mention the NCR at all.
Again I realize the show is borderline gibberish when it comes to its writing and the actual writers probably only used the NCR because some Bethesda consultant gave them the name, but its something that effects the larger Fallout Universe outside of their terrible show so I don't want it messed up. Really, Bethesda should have just said the show was an alternate continuity, if it wasn't official canon I could completely ignore it like every other terrible video game adaptation.