Call Of Duty: WW2 has the franchise back on top, and it may have never happened had some pesky executives not gotten in the way of Sledgehammer's initial idea. Activision CEO Eric Hirschberg said the initial pitch from the development studio was to create Advanced Warfare 2:

“Sledgehammer wanted to make Advanced Warfare 2. We knew they would become historians, that they would tackle it with authenticity, give it tremendous care, and we also knew they would capture the unspeakable scale of World War II."

While Advanced Warfare was a generally well-received title amongst the gaming community, it's safe to say the game may not have been as warmly received the second time around. Fans of the franchise had made it clear that after 3 titles they were growing weary of futuristic titles, and obviously a return to form won the franchise back a heap of fans. 

And it's not like a sequel to Advanced Warfare can't happen someday, although given WW2's success one might imagine COD will remain in the past for quite a while. Would you have been down to see Advanced Warfare 2 over WW2?

Source: GameSpot