I have already say that in the early days of gog supporting Linux, gog shouldn't have chosen to support Ubuntu. They should have chosen Debian, Arch, Fedora (or CentOS for LTS) instead of 2 versions of Ubuntu.
Alternative: just support Linux. State the required dependencies, but try to bundle as much as possible. IMO relying on the packages for any given distro too much was never a good idea; distros evolve and eventually people end up having to hunt for random outdated .so files to get their old Linux game working well on a new version of once-supported-in-the-past distro.
IMO supporting a specific distro is kinda like supporting a specific brand of PC (you need a Dell or HP to play this game!) instead of the internals. Doesn't that sound silly? It is.
I still have in mind how a few Linux native games sold here are currently very difficult to make them working on Fedora, or even unplayable because of libraries. The whole "curl and gnutls against openssl" thing for instance.
For example, I have to use Wine and the windows version to play Mount & Blade: Warband...
Idk, I've gamed on Fedora for a few years now and while there were a few hiccups, I always got things working if said things worked on Linux at all. I could've sworn I played Warband too.
So I believe that gog will drop "Linux" support since now Ubuntu drops good old games' support.
I'd say that's a poor prediction, but given how little GOG seems to care for Linux right now, yeah, I don't know..