Hikikomori Media reports that Smart Delivery game disks and Series games where you install the game from disk now do not need to be onlineto be able to install and play the game.
Backwards compatibility games (ie. OG and 360), Game Pass and stubs (games like Forza Horizon 5 and Halo Infinite) still require internet connectivity. You also still need to connect online to set up your Series X console for the first time.
(I’m pretty sure someone has already posted this- if so, I’ll delete my post)
Call back to previous threads: Possible Issue - You cannot play Installed Xbox One games offline on Xbox Series X - Gaming - XboxEra