From Press Release:
Prepare to welcome the Brotherhood of Steel to Appalachia in Steel Dawn, the next free update for all Fallout 76 players releasing December 1. Steel Dawn is the first chapter of the Brotherhood of Steel questline and expands on the new life brought to Appalachia from April’s Wastelanders update, adding new NPC’s, new locations to visit, C.A.M.P. Shelters for expanded building options, new weapons and armor to earn, and much more.
Alongside the return of the Brotherhood, Steel Dawn introduces a new Season (beginning December 15) and S.C.O.R.E. board as well as many additional improvements to the game.
To learn more about what players can expect in the free Steel Dawn update, check out this article here.