Who knows if they haven't already done it? Didn't they do that Red Baron thing not too long ago? I doubt someone whose job is also his (or one of his) chief hobby wouldn't have loose ends on his mind even after the commercial project is more or less concluded. IE if there was something wrong with the Red Baron sim's physics, I'd still be thinking about it today, even if just so it could provide an extra insight of some kind to the WWII modeling I were doing today.
Pyro said they have some stuff not shown, this is probably one of them. Someone in the 'How do you go about modeling airplanes' thread said that there was a common programming canvas to all planes, and that all (manner of speech) they had to do was plug in the numbers and QC that till it sticks to target numbers. With experience like Red Baron Pizza sim and DoA and anything else they've done on top of that, it probably wouldn't be so expensive development-wise.
Just on a hunch, my 2c.
And I don't see how we "can't" have any more WWII stuff unless WWI was started. That's nonsense.