Zacron: They have indeed released patches for their games, but they generally didn't need to. Myst End of Ages had several patches as did Uru Live. And although MOUL is no longer directly associated with Cyan, it does receive regular updates.
PraetorianWolfie: Huh. I didn't know that Myst End of Ages had several patches. I had the boxed version, and finished it with all its bugs and glitches (only one or two was game/immersion breaking). I'll have to look into that.
URU Live doesn't count for me. I was excluded (due to my country of origin) from almost every iteration, and even the last iteration of it (the free one) still has bugs that I reported years ago. Which of course still exist in the URU: CC offline version that is sold in gog.com.
My other (Cyan) Myst titles (Myst, Myst Masterpiece Edition, RealMyst, Riven) have also not gotten patches, though I could readily name annoying bugs for each of those too, so I wouldn't agree that they didn't release patches because their games didn't need them.
Let's hope that Cyan will be more reactive to user feedback with RealMyst: Masterpiece Edition
Well, when I say they didn't need them, I didn't mean that they were perfect games, I just meant that it didn't affect my enjoyment of them enough to, in my opinion, merit dedicating time and resources to them. I think they are fixing the patches and improving them more easily and successfully by releasing the masterpiece editions.
But yeah, EOA had at least 3 that I remember having to install to get it to run properly.
Keep in mind that the GOG versions are usually the most up to date versions of older games like that, and they come with the previous patches already installed.