In response to my Support message to Team17 asking about My Time At Portia (missing DLC), Neon Abyss (missing updates), and Overcooked 2 (which I thought was missing updates but actually isn't), they had this to say:

"We are trying to keep the GOG games

Unfortunately, the updates for the GOG version of My Time At Portia, Neon Abyss and Overcooked! 2 are not ready yet and we are unable to provide a specific date on which this update will be released.
But we can assure you we will do our best to release an update as quickly as possible."

I gotta be honest and say it's not super reassuring, especially since the person responding wasn't even aware that Overcooked 2 isn't outdated here. Sounds very much like a scripted response to me rather than a real one. We'll see though! At least it can't be said that they're unaware of it, and given that some Team17 games are kept up-to-date here just fine maybe it really will get fixed.

Human Fall Flat. I'm not sure if this game is still being sold on GoG, I think they removed it, but the final GoG update is missing levels that they only added to Steam.

Queen's Wish: The Conqueror

I want to buy it but Steam is v 1.1.1 and GOG v.1.03

I'll wait until they update game.

That is not true, GOG version is 1.1.1. on both windows and mac and was updated 29th November this year which was the same day as Steam.

The game has gotten the same updates as Steam every time.

They could be referring to the crossplay updates that are only on the Steam & Epic versions currently.

Jeez, from the sounds of things GOG needs some better quality control. The least developers/publishers can be expected to do is some upkeep for their GOG versions.

Team17 was one of my favourite publishers at some point, but these days ... they really don't give a shit about their GOG customers.

So Inscryption, nominated for the Best Indie at The Game Awards, and one of the Best Sellers on the GOG store, has a Beta channel on Steam to play the upcoming Kaycee’s Mod, but it is not available for GOG.

It is on beta channel for testing before full release. On steam it says they need testers so using steams beta channels to test before pushing out the full update is hardly second class treatment, if it doesn't come at full release then it's another story.

Since Inscryption is a game with a strong ARG, with secrets and puzzles to be solved by the community, I think it is relevant to have access to the same channels so that everyone can participate in this.
If we cannot play the Kaycee's Mod, we will only be able to read most of the ARG puzzles already solved and we will not be able to participate in the discussion. But I get your point.

ARG isn't really relevant here, beta is for testing so the developers can be sure it works fine before it's fully finished and especially for a single dev or those with few employees it isn't really viable to push out testing on multiple stores, Steam is large and that's where you get the vast majority of testers it's as simple as that.

Inscyption will still have all the content related to the game so we're not missing out on anything in the game itself, using external ARGs or events is going into a territory where literally anything and everything can be classified as second class treatment for any reason.

Good news everyone. Just had a little conversation with Kan from Freebirdgames regarding the fact that the Freebirdgames games weren't part of the Winter Sale before and I mentioned the missing soundtrack for "To The Moon" on GOG as well....

"Kan: d-(' ' d-) Thanks for the kind words Marko, and for the support! GOG will be adding them to the holiday sale roster later today if not already. I wasn't aware the soundtrack wasn't on there already, so will look into that too. Cheers~"

Death's Gambit has received the Afterlife update. Still no soundtrack, though.

Finally got a reply about the missing Japanese on the Kagura Games' titles (attached image).

Now waiting for a reply from the publisher of Agarest, but I wonder if they publisher of Agarest even cares at this point.

And about Jast, they said I should contact Ninetail (which I just did).

Should the Saints Row III remaster be mentioned? Until today there has been no patch that allows offline players to save their graphic options and some other stuff.