According to the latest reports, the new Call of Duty might not have a story campaign. Even though nothing is officially confirmed yet, it wouldn't be far-fetched to think these kinds of things possible. After all, this is Activision.
Call of Duty gets pumped out pretty much annually, and this year is no exception as we have images and trailers inbound for Call of Duty: Black Ops 4. Activision has handed Treyarch the reins for development, but have managed to cut them short of a single-player campaign.
What the game will have, according to anonymous reports, is a Battle Royale mode instead of the campaign. These are nothing but rumours, so nothing has been officially confirmed as Activision stated they do not comment on rumour and speculation.
Black Ops 4 had a relatively long development cycle which was basically cut short by Activision and slated for a 12 October 2018 release.
Treyarch couldn't have finished the campaign they were developing so they just weren't going to put it into the game at all. Perhaps we'll see it as DLC content and knowing Activision - that's more of a certainty than a possibility.
A community reveal event is scheduled for 17 May 2018, so more details about the game will be posted then for certain. Maybe Activision finally realised the story parts of their Call of Duty games weren't the selling point since the original Black Ops, despite the newest instalment getting some praise for its story.
Recently, the Call of Duty franchise delved into Second World War waters. Players were a bit surprised at the characters in single-player and the game felt bland in general. The multiplayer was littered with loot boxes and additional DLC offered little content for a whole lot of dough.
Call of Duty is a game everybody has played at one point in their life and most likely loved at one point too. However, the days of Call of Duty 2 or Call of Duty Modern Warfare are gone, replaced with new games which appear to have lost the magic touch the series once had.