https://www.techradar.com/news/call-of-duty-2018-release-date-news-and-rumors

Call of Duty is one of those franchises that you can count on. Like FIFA, it doesn’t miss its yearly slot on the release calendar and, to be frank, we like that kind of stability in our gaming lives. 

Activision has now confirmed that 2018 will see the release of another Call of Duty title and that Treyach is the studio working on it. Last year's Call of Duty WW2 was largely well-received and there was an uptick in the sales figures, so the decision to keep going with the series has surprised no one.