A tweet from Marcus Sellars offers an unconfirmed rumor that the next Call of Duty game will be Call of Duty: Black Ops 4, which will be set in the modern era. Marcus is a reviewer/editor for Nintendo websites, and MP1ST credits him for previously for correctly providing scoops on both Dark Souls and Labo coming to the Nintendo Switch. He does not, however, offer any indication of where his rumor originates. Here's word:

COD 2018 is Black Ops 4 and is coming to PS4/Xbox/PC/Switch. It is set in the modern times and is boots on the ground. The Switch version will support DLC, HD Rumble and motion controls. The Switch version is also being ported by a company which is familar with COD games.