T7 is by far the most popular CoD game on Steam which is ultimately what matters - not necessarily when the game was released. As far as we can tell we're fine and stay under the radar working on the games we currently support/have in the pipeline, but T7 specifically would almost certainly get the papers flying at a certain law firm.
Plutonium isn't just free games.
They, Activision still support MW2019.
Call of Duty Modern Warfare 2019 is on battle.net, which isn't easy to crack.
Either way, Plutonium isn't adding MW2019.