I'm going to suggest that they can already do this.

We know that Xbox won't let you use a second account to play games you purchased on your original account on the same device. One way to get around this was to use physical disks. But there's no stopping them from modifying the OS to read a disk already registered with one account and prevent that dial from being used on another account.

They are taking a shortcut though (probably to cut out the resale market) and just doing away with physical disks (just like Sony).