An OG timeline (FO1, FO2, Tactics, and FNV) and a Bethesda timeline (all the games/shows they made). I don't know why Bethesda didn't do this when they got the rights. It would make things easier for them. Due not having fans talk about how Bethesda broke the lore. Will, if they don't broke their lore. But you got my point.
EDIT About New Vegas. Bethesda didn't make it, but they did published it. So what timeline it belongs in? The reason I put it in the OG timeline. Because it being more similar with the OG games then Bethesda ones. But the show throws an monkey wrench into things. I guess New Vegas can be in both timelines.
EDIT 2 Both timelines can have the same factions, creatures so on. But the OG games are still canon in it's timeline. So everyone can be happy.
I can't think of any instances where bethesda messed with the original fallout lore before the show, although I haven't kept up with 76. Outside of that I would say the video games are all in one timeline and the show is the second timeline so that bethesda won't have to double down on anything in the show.
The show is canon now but I wonder if there is a chance they would ever treat it like Fallout Tactics or the Fallout Bible where it is non-canon but they borrow elements for games later on and those specific parts become canon.