It's pretty much official that CK2 is not coming to GOG.

The reason CK2 is not coming to GOG is that the multiplayer is based on steamworks, and redeveliping the multiplayer portion to use the stellaris framework (which is the reason we got stellaris on gog) would require a significant amount of work, which is not going to happen since the game is being discontinued.

I have no clue whether CK3 is using steamworks or the stellaris framework. If the former, we are not going to see it on gog. If the latter, we have a hope to eventually see it on GOG. I am hoping for the latter, since I would rather give my money to GOG and then decide what to do with my game that I paid

As opposed to being forced to update when the game decides it's time for me to update, or being flat out unable to play thw game i both BOUGHT and INSTALLED because the DRM decides I HAVE to update steam NOW and I currently don't have an internet connection.

Now, if GOG decides to develop a steamworks-compatible multiplayer inrastructure, then we might see CK2 on GOG... But CDPR is trying to make a fair living providing fair deals. Which sometimes means they lack the resources required to throw a few containers of dollar bills at a problem.