I mean... Do they even want to? Sure you can "mix it up", but if mixing it up, means that one team has to go back and just basically recreate what's already been done in the series, that would be just boring. At least with future, they can be creative.
Not really? I'd say going back is far worse. What else can they do? No one has answered that question. At least with future we can start to see stories with less than perdictable outcomes.
Okay, so I want to ask this question again, since no one answers it. Okay, so innovation doesn't mean you need a new setting. That is 150% true. However, i'd argue that they can't really "innovate" that much in Modern and WW2 settings without starting to become other games. So I'll ask again, what can they do now in those settings, that they didn't do before?