MCC online needs more then a patch, it needs rewriting from the ground up to get it working, hopefully that's what is going on.
Originally Posted by Jrs3000
MCC issues were multiplayer involving all the online being put together. Totally different story. Singleplayer was fine in MCC.
EDIT: Single player Had issues but wasn't broken
It has a few problems here and there, most of the bugs were fixed in early patches like halo 4 going black screen in some loading zones, I never did finish halo 2 anniversary but that was because co-op online was desyncing and impossible to finish.