The Brotherhood of Steel has a nack of just appearing out of nowhere - and indeed that's exactly what they've done in Fallout 76 - with the latest expansion, Steel Dawn, releasing a week earlier than expected.
The new expansion was slated for the 1st of December but was dropped unexpectedly early, to much delight, last night. It's available right now on both PC and consoles, according to Bethesda.
Today we're releasing our Steel Dawn update for #Fallout76 ahead of schedule! You will be able to experience the all-new Steel Dawn questline, your very own C.A.M.P. Shelter, and more!— Bethesda Game Studios (@BethesdaStudios) November 24, 2020
Patch notes can be found here: https://t.co/6xHMKfNwP4 pic.twitter.com/kTql1VMQjL
The reason for this isn't entirely random - it appears that there were issues with players on the Xbox platform getting the expansion before the actual release date - instead of trying to undo the damage and revert those players, Bethesda instead decided to just roll with it, and release the update for everyone on all platforms.