The concept of Infinite Warfare is actually... really funny. I mean, what'll they do next? They've shot themselves in the foot. They can't go beyond Infinite.
NOTE: In an exhausted haze I realized that I forgot to apply links to the buttons below. I apologize for that, they've been fixed to work properly!
Oh Sarah, do you really think a concept as mundane as infinity would be enough to stop Activision from continuing such a profitable game franchise? It actually isn't that hard to imagine. I mean, Marvel solved this very problem years ago for comics - whenever a conflict or plotline escalated to the point of universal scale, they just end up rebooting the damn universe. In the case of CoD, I would be completely unsurprised if Activision chose to reboot the series and revisit the old WWII setting.