https://www.polygon.com/2018/5/17/17364796/call-of-duty-black-ops-4-pc-battle-net

When Call of Duty: Black Ops 4 launches on PC it will be exclusive to Battle.net, Activision announced today. The PC version will launch the same date as console editions, Oct. 12.

Beenox is handling development of Black Ops 4 on PC. The Activision subsidiary most recently developed the remastered version of Call of Duty 4: Modern Warfare that launched in 2016.