Yup, intermit patches may break your saves... and savegames made now will NOT work in the final version.
Just an FYI, if you're mid playthrough and Larian releases a patch that breaks saves you can still finish it if you do the following:
1. Set the game to "only update when I launch".
2. When you launch steam, if you see a patch pending for D:OS 2 shut down steam and start it in offline mode.
3. Play the game unpatched.
Obviously any such feedback you'd provide on an old patch should come with caveat; but if you find yourself in the middle of a game and want to finish, that's the way to do it.