Don't try to backpedal, this line of your means nothing unless you meants the game shouldn't have anything from past games, because they could just make something new
Same way books written in the 4th era appear in dungeons sealed since the early 1st in a TES game, or why there is some magical force field preventing you from even attempting to hack computers until you meet a certain skill threshold, or even better yet, why skills and attributes are somehow turned into a straight linear progression of 1-100 in RPGs, when neither skills or attributes are actually linear in the real world.
Its a GAME dude, not a 100% accurate simulation.
Saying its illogical for jet to have gone to the other coast is as absurd as saying its illogical for skooma to be in Skyrim because Tamriel is the size of Africa, over three times the size of America, over 4 times the size of the Roman Empire at its greatest extent, and when Elswyer is on the other side of Tamriel from Skyrim.
Stuff moves m8, even as far back as Fallout 1 we had people like Tycho moving half way across the country and back again, the idea that it wouldn't have gotten over to the east coast in over 30 years is silly.