I don't know what's happening with the game's updates, but it certainly looks bad when the game updated on steam, and I can't get the update here. If someone could explain why the update is coming out late on gog, that would be much appreciated.

The update looks great, can't wait to play it.
https://www.youtube.com/watch?v=SNMJ86U4oiA
From what I'm hearing it isn't yet available on XBOX One as well, just give it a day or two.

I've been asking this a few times the past 4 days on the Hinterland forums. http://www.hinterlandforums.com/
The first time (Thursday) I got a reaction from Raphael saying they were still working on the GOG build. So that sounds promising. But that's the only information I have. There's nowhere stated if and why the GOG version is delayed. This is not something I'm used to with Hinterland. They've always been very responsive and I have a high trust in them because their communication is fantastic. Except about GOG... for some reason questions about the Xbox and Steam get answered right away or within a few hours but my questions about GOG have been ignored the past 3 days (except Raphael van Lierop who reacted very quick, again thank you it's much appreciated).

TL;DR
Raphael van Lierop stated last Thursday that the GOG build is currently being worked on. There's no other information on the official forums about why the update is delayed for GOG.

Maybe it is related to the new update system GOG has been testing recently. I know The Long Dark is using it... but I'm just guessing right now. I hope Hinterland can give us some information. I'm not demanding a release, I just want to know if GOG players aren't forgotten and what the current progress is. Heck I rather wait another month to get a stable build instead of a rushed and bugged one. :)

Also about the Xbox, this topic seems to confirm that it did received the update on the same day as Steam. "Please note the Xbox release version of “Tireless Menace” is v.320; the difference between v.320 and v.321 are Steam-centric fixes."

I got reaction from Hinterland after I send them a message earlier today. They've said that they are currently supporting multiple platforms which is why the update is taking some longer to release on GOG.

I remember seeing a topic around here where people asked for the Linux version. So I think Hinterland wants to release the new version(s) to all the platforms they currently support and they probably want to do that all at once on GOG. Seems fair to me.

I'm glad I got an answer from them. Feels better now knowing they are working on it. Thank you Hinterland! :D

Also be aware that GOG updates don't work like steam updates.

Developers directly upload their updates to steam. On GOG, the developers send their stuff to GOG, who then go through their own quality assurance testing before uploading the update, this sometimes makes it so that the update takes several days to appear on GOG. I have no problem with this. Sure, I like them sooner rather than later, who wouldn't? Buuuut, there's still no rush for things or any reason to get uppity (not saying you are at all OP, I'm talking in general) about it. Get uppity about other things, like poisoned water supplies and massive overpopulation and such.

It's here. It's here. Two days ago I commented to Hinterland's YouTube under their "Tireless Menace" video that GOG was still stuck on v. 302. Today when I opened galaxy The Long Dark updated to version v.332. I'm so excited.

The Challenges mode has now been added.

Check it out. :)

Yeah I noticed it too, I'm currently downloading the patch. It's going slow though, it goes up and down between 0,3 and 0,7 MB/sec (my connection allows 6 MB/sec). But I can wait, I've to eat my ridiculous large storage of wolf meat first before I apply the patch so I don't get ill. xD
I immediately messaged Hinterland to thank them for the release. So exciting, it feels like getting a present! :D