Why Fallout 76 Changes Series' Lore (Including The Brotherhood Of Steel)

Bethesda says it doesn't want to be "beholden to something that somebody wrote 20 years ago," but still comes up with in-universe explanations.

Our developers take things like lore and canon seriously and if they're going to do something they're going to make sure that there's a real and defensible reason for it," he said. "We have proven with Elder Scrolls games, we're willing to say 'Well lots of people will say things happened one way,' and the opposite or something else could entirely be true. So there's no question that we've gone back to change things to fit what developers have wanted to do and not be beholden to something that somebody wrote 20 years ago even in franchises that we created like the Elder Scrolls.

But having said that, we don't take it lightly to just go 'Ah, we're just going to do whatever the hell we want.' There has to be a thought process--what is the rationale? Why would this logically work in this time? Why would there be super mutants, or the Brotherhood of Steel? How does that all fit and hold together? There's absolutely reasons and explanations for how all that ties to Fallout 76.