I'm not really reading to much into statement, could easily just keep warzone only as you say.to be honest Phil statement can be interpret in many ways, also that warzone stay and they will fullfill existing agreements and after that no new cod
Although unlikely as COD is just too big a title to shelve.
I'm just thinking how they could make best use of COD and studios, and even if was still multi plat, Sony could still end up missing out. Just side affect.
Will open market for someone else if they did that though.
With so many studios and IP really have some options for release cadence and variety.