It looks like Call of Duty: Black Ops 4 will be available on Battle.net.
This comes ahead of an expected announcement of Call of Duty: Black Ops 4, which Eurogamer first reported on in February.
Activision has form when it comes to launching its PC games on Blizzard's platform. Bungie's Destiny 2 came out on Battle.net after it launched on console. It looks like Call of Duty will follow suit.