After Microsoft acquired Activision Blizzard, one of the first things people theorized was that the company would have one of Activision’s numerous Call of Duty studios work on Halo. That already happened, according to a new report, and though it hasn’t led to anything yet, that could change down the road. According to Rebs Gaming, who has accurately reported on unannounced Halo news before, Microsoft enlisted Sledgehammer Games to help develop a Halo multiplayer game. Halo Infinite Sledgehammer reportedly began…