Activision did have a deal with Microsoft in the past during the last generation of consoles. Xbox 360 used to get CoD DLC early. That contract ended and Sony made a new deal with Activision. Sony used to get have a deal with EA and they got Battlefield 3 DLC early, but then Xbox got BF4 DLC early. This type of thing happens all the time. I don't think it's as complicated as people seem to think. I don't believe Bungie holds any resentment towards Microsoft or the other way around. They just parted ways in fairly positive way. Obviously not all break-ups are drama free though. A few employees were unhappy with the decision and some stayed with Microsoft to keep working on Halo. But I don't think there's any bad blood between them.