Clearing up a misconception, the Activision/Blizzard deal is not about getting more exclusives. TL;DR: A/B deal is about increasing revenue for Xbox, not getting more exclusives. Games like COD or Diablo are never going to be exclusive because they make too much money on other platforms.
Microsoft Now Owns Activision Blizzard: What It Means for Your Favorite Games. Overwatch, Call of Duty and World of Warcraft are now all owned by Microsoft.