Hah. But these are self-contained universes which need to maintain their integrity in order for us to respect them, otherwise why not have Mario or Sonic cameo in CP77.
The only factor in common with these gameverses is that CDPR created them, and that's not enough to expect a reasonable crossover. I like the Ciri idea because there's a way to rationalize her existence.
Alternatively, the witcher game could be shown to exist in the CP77 world, and maybe people cosplay as Geralt and co., that would be cool, haha.
But if the idea is to just have fun, then yeah, it's possible to do that. I mean, I won't get mad if the real Geralt shows up in CP77, but it will make the witcherverse a bit comical for me.
Sorry for the serious post, Sard, I know I'm just supposed to joke around or abuse you since that's all that makes an impact on you, but I guess I'm in a different mood today.