I'm an executive crisis management consultant. I know exactly what anger is being thrown around, I deal with it every day. I do NOT know the nature of Bungie's contract with Activision but since they're the 'above the title credit', someone there is screaming for heads to roll and lawyers were called.
Moreover, any professional business (obviously not the dillettantes at Bungie) knows that dramatic change requires management that lowers resistance and gains acceptance - gradually.
The unexpected and I'll conceived timing on this news bomb was pure amateur hour and ANY (every) partner of that would be rightfully livid.