With all eyes on the upcoming Call of Duty: Black Ops Cold War, which will be receiving an open multiplayer beta next month, it would be safe to assume that that was Activision's main focus, alongside continuing to support Modern Warfare, Call of Duty Mobile, and Call of Duty: Warzone. However, it appears that Activision does indeed have another Call of Duty project in the pipeline.
This comes from a new job listing on Activision's own website. Usually, job listings such as this don't confirm new games. For example, studio NetherRealm posted job listings which suggested that new Mortal Kombat and Injustice games are in the works, but it didn't confirm exact titles or any new details. This job listing, though, which is for an executive producer role, straight up confirms that Activision will be porting Call of Duty: Warzone to mobile devices.
Aside from featuring the codename WZM (which can only be referring to Warzone Mobile), the listing specifically talks about delivering essential features from Call of Duty: Warzone into their "best mobile instantiation" and improving the formula by coming up with mobile-specific additions. The name Warzone Mobile is even mentioned, with the candidate needing to serve as the primary point of contact on Warzone Mobile's leadership team.
It seems a bit weird for Activision to bring the battle royale game to mobile devices when it already has Call of Duty Mobile, which is free-to-play and also has its own battle royale mode. On the other hand, given Warzone's continued success, Activision likely wants it on as many platforms as possible.
It would certainly give Activison an edge over Epic Games and Fortnite, due to the latter's ongoing dispute with Apple and Google resulting in Fortnite being removed from both app stores, meaning mobile Fortnite players have been unable to update the game to Season 4.
There's no indication of when the mobile port will arrive but, given that Activision is still hiring for it, it's likely that the project is still in the early stages of development and probably won't be out for a while. We can only speculate, but our best guess is that it won't release until next year, as Black Ops Cold War is releasing this November and it wouldn't make sense for them to release so close together.
There's still quite a bit we still don't know about Black Ops Cold War, with zombies only recently teased in some official capacity. It's not clear whether the game will come with a traditional zombie mode, though, or if zombies will also arrive in Warzone.
Call of Duty: Warzone is available on PC, PlayStation 4, and Xbox One.
Source: Activision