Originally Posted by stubbie
The hotfix is an official patch released by Larian.

No, it's an update released by GOG to correct an error with the previous patch, affecting French and German users. GOG produce their patches based on updates they receive from developers, and they decide what pre-install checks each one makes.
Originally Posted by stubbie
So what happens when the next patch released by Larian requires me to be fully patched and up to date?
That patch could well tell me that I don't have a current up to date game so please update.
It could, but hotfixes are typically considered outside the normal patching regime so it seems unlikely. It's even possible for the opposite - later patches refusing to install over the hotfix. Until the next GOG update is released, no-one can be sure so it's of little use speculating.

And not every GOG patch has required the latest version - the current patch for D:OS will update from 1.0.74 to 1.0.107, without needing the 1.0.81 update.