Modern Warfare 2, Warzone 2, and all future Call of Duty games will be on one "unified engine"

gamesradar.com:

The developers behind Call of Duty are moving to a single, unified engine across games and studios, starting with Modern Warfare 2 and Warzone 2.

All the various studios working on Call of Duty, including Infinity Ward, Sledgehammer, Raven, and Treyarch, will now be working on a single engine for every new entry in the series going forward. Internally, the developers are referring to this initiative as COD 2.0 - and while that name may not make it past development interviews, it does hint at the direction this new era of Call of Duty is taking. 

"When one of the teams puts in a really cool rendering or audio or animation feature," communications director Stephanie Snowden told GamesRadar+, "then we have to have a bunch of people implement it in the other engine, and then another engine again." The new engine model is intended to eliminate that issue, so each studio can directly contribute to the work of the others.

As for the starting point of this new engine, "there's a large chunk of it that from what I suppose you probably thought of as the IW engine," Snowden says, adding that "there was a large chunk from our other teams as well that got integrated into that."

Snowden admits that "there's challenges associated with it in terms of merges and branches and things like that. But I would say that it's been only for the better, because we ended up getting the best of the best of the best of the best features. And we have the best of our engineers in any particular area, working on this technology that we're all making use of."

Despite the development advantages of a unified engine, Snowden says the team is "mindful" that COD games might "homogenize" under this tact, an issue the devs are keen to avoid.

"A Black Ops game