On steam there is a page for Geneforge 1 Mutagen which I think is going to be a remake of the first game. Do you think it will come to GOG as well?

Well, basically all the other Spiderweb titles have come here with no hitch. In due time, I presume.

The new Geneforge Mutagen is expected to release by February 2021 as per steam. So, let's wait as it is not yet released in steam but only the page is there, I hope that the GOG page comes up by next month or two.