It seems at some point over the last month or two, GOG finally removed the "in progress" notice for GOG Galaxy coming to Linux.
Something that was a bit overdue, since they clearly have no plans to actually bring GOG Galaxy to Linux despite it being the most voted-for feature request for many years. GOG and CD Projekt never really took it seriously though, with even the official Cyberpunk 2077 Twitter account trolling "We can assure you: it‘s not us. We are the driving force behind 'add Linux support for GOG Galaxy' though" in reply to GOG post about showing 2077 gameplay.
Every time I've spoken to the GOG team over the last few years, they just repeatedly told me it wasn't planned, despite the wishlist entry still listing it as "in progress" and their original announcement mentioning it would come to Linux too and that it was "being done with PC, Mac and Linux in mind" (so much for that huh?).
At least there's applications like the Heroic Games Launcher and Lutris that can help you manage your GOG games on Linux. Still, it would be nice if GOG at some point put some more resources into improving their Linux support. Plus, if you're going to be using a Steam Deck, buying from Steam just makes a lot more sense when it's far easier to access so I imagine that's eventually going to cost GOG a few more sales too and they're not exactly doing well.
It is a shame for those that want the Galaxy client, as I actually love what GOG do. The main idea that you can just log in and download a full offline installer is great and their repeated revivals of old games is wonderful too. But without Galaxy, some games end up missing features for Linux or just skipping a Linux build entirely on GOG.