Agree on that. I just played the game for the first time and how the DLC is integrated and promoted in-game is breaking the immersion and, given the DLC isn't even available, somewhat insulting.
When the game was on sale a week ago, I refrained from buying it after reading about what content is missing, I wrote to GOG support and stated that I really would like to buy the game, but I could not support a developer who does not fully support the platform he sells his product on.
I received a reply during last week, stating they are still working on this, it would be complicated and they could not disclose any details right now.
So I jumped the shark during the final sale and bought it, I really liked what I saw up until now, but I would definitely appreciate if they could just release the missing content on GOG, already.
Including the soundtrack, which is by Jeff van Dyck, who is, for example, the composer for Total War Shogun 2, but it appears to me that the OST is not a priority for GOG at the moment. Getting the soundtrack together with a game was, besides the DRM-free mindset, one my main reasons to start using GOG back then. In some cases, the OST for a game isn't even available here for purchase, though elsewhere it is. Double Fine's games come to mind...
Edit 2 days later:
Yay, progress! ( http://www.gog.com/game/hand_of_fate_wildcards