Folks, let's face it, this isn't the 1st nor it'll be the last time.
Games like "Saints Row IV" or "Lost Ember" or many others were similarity made not working on Windows 7 out of the box, while "No Man's Sky" has phased out Windows 7 overtime without changing the GOG page. I won't even longmention in-depth the fact that many games like "Ashes of the Singularity: Escalation" have not received the latest update as it is on Steam, are basically abandoned, or that games like "Mechwarrior 5" scream about a missing Windows 10 DLL (that doesn't prevent launch, it is used for debug, not important but quite annoying). It does not help that games like "Bite the Bullet" and "Comanche" do freeze to death on having LAN plugged-in without the Internet access, or how "Beat Hazard 2" is under Online DRM and won't work offline at all, this all is so wrong, the store doesn't do a thing to prevent it. Too many issues that stand unresolved forever, folks!
The truth is GOG doesn't care and likely wouldn't care in the future, it certainly doesn't honour you the customers, it won't do as little as to just autodownload a product from its own GOG Galaxy and automatically launch on 7/8.1/10 (or whatever the supported systems are) to see an error popup that demonstrating that the page must be corrected or the developer shall fix the compatibility issue instantly: Not full testing, mind you, just launch and quit, it won't take more than 8–16 workdays of 1 employee per OS for all the games, assuming it's pre-downloaded. In an ideal world, GOG could care, do basic quality control, but, we are in the realm of negligence, it very sadly seems so, where GOG has grown numb. I truly do wish that wasn't the case.
What can you do as a mere customer like myself? Do not trust GOG Galaxy for storage, do keep tested offline installers, never expect GOG/devs to care about your compatibility, do not pay for games whose developers do misbehave such rotten ways deliberately. Not much can be done beyond that for now.