As soon as you put a physical disc into a console, it immediately ignores its contents and downloads all new code. In this way, the physical disc is simply a physical DRM. At some point, the game has to be saved in some state well in advance of release date to manufacture/ship said physical disc with enough time to have it be available for release date. Back when I was last involved with physical shiny round discs back in 2007, it was minimum 6-8 weeks. That's forever in game dev for changes to be made so that the content on the disc is probably just heavy assets used by whatever is downloaded.