Cavalary: That's quite nasty of them, with just an update like that, since there are still some users of that (obviously) and, unlike XP, it's still technically under official support from MS until April. If anything, third party devs should strive to support older OSs even after the end of official extended support, not end it sooner.
(Assuming it doesn't have support for XP either? Thinking there are still a fair number more users of XP than Vista.)
Except that Galaxy officially never supported XP nor Vista. Since the day it was made available it only ever claimed to support Windows 7 a nd newer. The code just happened to work on XP and Vista also and they may have tweaked it a bit just as a convenience to those platforms even though they were unsupported, but since day one they said that they would try to do that as long as they could but eventually a day would come where it would no longer run on XP or Vista.
It's not nasty of them to upgrade it to support missing features on supported platforms right now and lose the ability to run on always-unsupported platforms, rather it was very incredibly nice of them to have left code in the program to let it run on unsupported platforms from release until now. I have to pat them on the back for their generosity towards people who are using older platforms all this time as they didn't need to do that, and they not only never claimed to support XP or Vista, but they officially claimed that they were unsupported, so they did not even miscommunicate about it.
So while nobody else is really saying it, I'll say this even if it is unpopular to some:
Good job GOG! Thank you for allowing Galaxy to have run on XP and Vista all of this time even though you never supported it officially and you clearly communicated that to us all along, it was a kind gesture to legacy OS users. Thank you also for upgrading Galaxy's underlying technologies to support H264 video codecs so that people can see more trailers instead of broken video, and for upgrading the other core technologies to improve the performance of the client and other capabilities on the supported platforms. It's unfortunate that you were not able to continue to make the client able to be ran in an unsupported state on legacy OSs, but at least you did your best to make it usable as long as possible on them.