So I was doing a little searching to try and make sense of the show's timeline, and I found this on the fallout wiki.
This is the set for the Vault 4 Classroom from season 1, including the Infamous chalkboard which lead to the "Fall of Shady Sands" lore date of 2277, except...
That isn't the date on this chalkboard, it's actually
2291.
The Fall of Shady Sands originally took place in 2291, not 2277. It was changed afterwards to 2277. I seriously believe now that the 2277 date was a fuck up and was never actually intended, but the people in charge of the whiteboard realized that 2291 was too close to the year the show took place (2296), so they pushed it back to 19 years before the show took place, but this accidentally ended up retconning New Vegas. Everything afterwards, Todd stating in a IGN interview that the "Fall of Shady Sands" wasn't actually the same as the Nuking, and that the Nuking takes place after New Vegas, was just a desperate attempt to fix a fuck up, the show was never supposed to retcon New Vegas, it was only supposed to retcon the location of Shady Sands. Todd, and the show runners, couldn't just admit they fucked up the date, "fixed" it, and then accidentally set it too early. So the "Fall of Shady Sands" was turned into a different event from the Nuking.
The script for episode 1 is publicly available, and in it it states that Maximus is 6 at the time of the Nuking of Shady Sands, and 19 at the time of the first episode. This puts the Nuking of Shady Sands in 2283, a much more reasonable date. The 2291 date is still baffling, unless you assume the TV show was set in a later year originally, like 2304.