Big No
Watch as I open and close this door
I mean, technically that's Fanon. Canon is what the IP holder dictates what happened, Fanon is what the fan imagines what happened."Canon" is just a piece of paper that says "Beth owns this IP now"
To me Resurrection is Canon, Nevada is Canon; Underrail is Fallout 77 or something.
This is the exact same argument with Disney.
New "Canon" IPs may shit on the previous ones for sure but they don't UNDO the experiences you had.
We could say AlChestBreach's Brahmin Hunter saga is canon but don't expect to see literally anything regarding it in any Fallout installment.