Interesting that this sometimes appear on page My progress in Witcher 2 in GOG 2.0 , but after some time it dissappears.
ctrlv.cz/7RuA
btw some time ago in my library also appeared Overlay 2, but after day or two it was gone

I can see them as well (attached file). Either they're getting ready to start testing them or this is a remnant from all those years ago when achievement support was added to Galaxy. It would be really nice if they somehow managed to add them before the end of the year.

Thanks to the Netflix show, sales of The Witcher have increased again, so it would be great if they took the opportunity to finally add the achievements to The Witcher 2.