Will Sledgehammer Games make COD in 2021? All sources point that way.
Advanced Warfare 2 - or - Modern Warfare 2 - or - World War 2 (pt 2.)
So there is 3 ways this could go, both of which include titles we've seen being brought back to light.
Advanced Warfare 2 would see us return to jetpacks, which would be a change from the past 3 cod titles. Would you like to go back to jetpacks, I'd say the MLG events were the most hype when we had this extra gameplay element.
Modern Warfare was made by infinity ward, so it's unlikely we'd see sledgehammer take the reigns here. However, never say never in the world of cod.
World War 2 (pt 2.) would be a very likely bet. In my personal opinion, I really hope we don't go this route. This game was pretty stale in the competitive scene, but did introduce the best ranked system in cod to date. World War 2 changed from its realism roots to a more cartoon, fun style mid year - as the head of the studio parted ways.
What do you want to see? I'd love to see something familiar but fresh!