Most of the work been towards the HDD and NAND, the Disc is basically useless this time around, it is nothing but one giant container that is copied to your XB1 HDD, there really not even any protection on the disc itself or the transfer, as everything is done on the HDD side for auth. and verify afterwards, the disc is just useless add-on that was put there to please physical retail stores, and the XB1 is designed security wise to become a disc-less network-run console.
Think of the disc as an internet download recording, its nothing more then the package you get transmitted to you when you buy a game digitally.
How would you explain the need for the disc to be present in order for the game to boot (when a physical copy is purchased)? There must be some sort of disc based authentication. Then again, I understand where you are coming from, but I presume a special token/license must be present and either it is linked to your account when you make a digital purchase or it is physically on the disc when bought in store. No?