If your console allows you to play disc purchased games without the disc in the console, then being able to "deactivate" the disc on the web before reselling it

If your console allows you to play disc purchased games without the disc in the console, then being able to "deactivate" the disc on the web before reselling it would allow you to continue to play your game on your un-networked console. You can't have disc-less disc games that allow trading and don't require some form of "always on". You have to give up one of those; this time around it seems they are giving up "disc-less disc".