I’d like one based around C&C Red Alert (and the sequels), then it’s a different war no one else will have done, but without being an entirely fantasy/sci-fi setting. Still mostly contemporary (or at least 20th century) stuff, but with scope to allow the weird shit that happens in those games. Alternatively, whatever other alternate history scenario they can dream up for the sake of avoiding issues over the IP.
I think we’ve run out of real-world conflicts that would make compelling FPS games; pre 20th century it’s a different type of game due to the way firearms work, though you could probably scrape enough other wars to do some kind of anthology for the single player (similar to bf1) and just dump all the assets into the traditional multiplayer game modes; Falklands, Suez, Bosnia, Korea, Mau Mau Uprising (Kenya?), Aden/Yemen. The types of warfare involved wouldn’t flesh out a whole game but they could fit specific scenarios.
I’m not particularly WW2ed out; there’s been a bunch of games but I think the last one i played significantly was Heroes and Generals which is a few years ago now. If it was just a remake of 1942 on the BF1 engine then I’d probably be pretty satisfied. Before H&G it’d be getting back to W:ET which is over a decade ago. Didn’t get into Hell let loose, or Day of Infamy (yet) on account of the gameplay and lack of players respectively, and that 30-40 minutes i wasted on that recent CoD beta doesn’t count; again it was the gameplay that held no appeal.
I can definitely see Atlantic/Pacific/North African theaters being different DLC, with central/western europe being the core campaign stuff.