I haven't played Halo 4 for at least a week, so I don't know if I've had that problem, but my control layout in HCEA got reset to default. I use the "Duke" layout, so I pressed RB expecting to turn on my flashlight and instead executed a melee. Also, I got that initial message when you first get the game that talks about the Anniversary Map Pack. However, I didn't lose any of my Campaign progress, and was still able to play Two Betrayals with a buddy of mine.