What wait you cant refuse game updates?
People are misunderstanding. You can refuse the update, but if you don't accept it then you can't connect to Xbox Live while playing.
Even if the update is necessary in order to play online co-op, there should still be the option to decline the update and play single-player only while still connected to Xbox Live.
I only play co-op with a friend personally. Otherwise I always set my game to private so no one drops in. I and anyone else in a similar situation ought to be able to play the game while connected to Live so long as we are playing in a private, non co-op game. This is where the "mandatory" nature comes in, especially if you're into unlocking achievements, because you have to be connected to live to unlock achievements, so you would eventually be forced to accept the update if only to connect to live and pop any achievements you've earned offline.
It's a tad asinine to force the update on people, but sort of understandable for co-op play. They just need to allow solo players to decline it and still play online in solo mode. That would solve a lot of grief and bandwidth cap concerns.
That's an insane patch. Super Mario 3D World as a whole game was less than 2gb. Think about that..
While I agree the update size is insane, it's disingenuous to try and compare it to SM3DW. The only apt comparison is between other PS4/XB1 games with open-world free-roaming settings where the environments alone are many scales of magnitude larger than Mario.