Starting with Call of Duty: Black Ops 4 in 2017, Activision stopped sharing Call of Duty games on Steam and moved the games to Battle.net. However, until then, all Call of Duty games were released on Steam, and all those old games are still available on Steam.
If we count those that are not on Steam, we can say that all Call of Duty games since then. Modern Warfare, Warzone, Black Ops Cold War, Vanguard. These are not available on Steam.
However, a banner that appears on the Call of Duty DLC pages on Steam indicates that their work will change. The image, which was noticed by garysplay on Reddit and was removed in a short time, is Lt. Simon, who is also in the cover art of Modern Warfare 2; Ghost; He was pointing to Riley.
The place of this image is now empty, but as you know, something that falls on the internet remains on the internet 🙂
The fact that the series will return to Steam shouldn’t come as a big surprise, because Microsoft is buying Activision Blizzard, and the same Microsoft is sharing more and more first-party games on Steam. Therefore, it will be quite normal for the series to find its place on Steam again from now on.