How the Call of Duty Modern Warfare series will continue alongside the remaster editions is still completely open. Infinity Ward itself now suggests a direct sequel.
As far as we know by now, Alex, who ended up sacrificing himself with an explosion, is still alive. While it was previously assumed that this was simply a way of summarizing the ending, a tweet from narrative director Taylor Kurosaki is now causing new speculations.
A fan on Twitter said that he hopes to see Alex again in a sequel, to which Kurosaki replied: