https://www.gamespot.com/articles/why-call-of-duty-black-ops-4-doesnt-have-a-traditi/1100-6461777/

Breaking with tradition, this year's Call of Duty: Black Ops 4 does not feature a traditional campaign. But why? Treyarch design director David Vonderhaar and studio head Dan Bunting answer that question in a new video from Game Informer.

"Development is a journey," co studio head Dan Bunting said. "We try a lot of different ideas and a lot of different things. The game that we are making has evolved over time, and that's just a part of development. I can't remember a single game that we've made that hasn't had a dramatic change in the prototyping stage. That's what prototyping is for. You prototype ideas; some of them work out great, some of them don't work out great and you pivot. You find a new idea [and] focus on that. We follow the fun."