If there will be a sequal I think it should stay in the WWI. Appearantly, some people don't seem to realise that there's a huge difference between the first and the second world war. The whole game is based on trenches, which didn't play a big role in the WWII. That's exactly why it's nonsense that it'd be easy to do. Also, Devious, why say that trenches weren't the key thing of the WWI, it's about the game, and in the game, trenches are the key thing. But anyways, even without another story to the game, there are lots of things you could add to the game to give it more depth, like influence of weather conditions, new troops, the ability to create and place mines and barbed wire, etc. I think adding more countries would also be a nice idea! It would be a great surprise to me if the game would go back even further, to for example earlier in the WWI or some other, less well-know war.
Trenches were important but there was also town warfare, forts like vimy ridge, and forests. What I am trying to say is that there are more options then just trenches.
I think that there's no question whether or not it should have a sequel, the question is what war would it be? I think another WWI would be good, but I'm sure the same basic concept could be adapted for any other war. I mean, we're talking about the developers who not only gave us Warfare 1917, but The Last Stand 1 and 2, as well as SIn Mark, which I feel is an incredibly underrated game.
Did someone actually suggest that CANADA and France be added to the next game? Really, Canada? What contribution have they ever made to any war? Our Salvation Army could beat them! And France? By the time any battles were fought they had all surrendered and were POW's! There could be an automatic surrender icon with the French flag maybe.