https://www.polygon.com/2018/5/17/17364846/call-of-duty-black-ops-4-no-campaign-treyarch

Call of Duty: Black Ops 4 developer Treyarch acknowledged this week that the game will not include a standard single-player story campaign, making it the first mainline entry in the franchise to do so.

The news confirms what Polygon reported last month, based on multiple sources: Treyarch decided to scrap an unfinished Black Ops 4 campaign and focus instead on multiplayer components, in the form of the Call of Duty series’ traditional competitive multiplayer package and its cooperative Zombies mode.