I think what he meant by that is that halo 2 was the first halo game to have full fledged online multiplayer. And it kinda kickstarted that aspect in console games. So not having multiplayer this time around wouldn't be something he would be ok with.Ehh, that campaign was sort of a disaster. My friends and I must have played through the CE campaign 30 times together, and I couldn't get any of them to play through Halo 2's campaign even once.
I seem to remember Phil Spencer tweeting about this. IIRC, he said that a theoretical H2A release would only make sense if they came correct with the multiplayer this time.