SCPM: Shortest Trip to Earth is on the list, but the DLC it was missing was released in February according to GOGDB, so it can be taken down.
And there's a list of some of the games on the list missing DLC that do have product ID numbers in GOG's API:
Product ID# - Title 1074003868 - Party Hard: High Crimes
1113578050 - Warhammer: Chaosbane - Base Fragment Boost
1280789344 - Warhammer: Chaosbane - Gold Boost
1393993507 - Warhammer: Chaosbane - Slayer Skull Pack
1398898807 - Chernobylite White Rose Pack
1463679578 - Niffelheim Odin`s Blessing DLC
1672764200 - My Time At Portia - NPC Attire Package
1709835092 - Niffelheim Bloody Moon DLC
1877531867 - Warhammer: Chaosbane - 4K Package
1896749166 - My Time At Portia - Player Attire Package
1946230305 - Offworld Trading Company - Interdimensional DLC
1948064082 - My Time At Portia - Swimwear
2055127276 - EARTHLOCK: Comic Book #2
2092178015 - Two Worlds II: Shattered Embrace
So the question is whether we are waiting on GOG or for the developers/publishers for these to be made available, and how much longer we will need to wait.
You can see any DLC for a title through the Galaxy API, for example:
https://api.gog.com/products/1472128402?expand=downloads,expanded_dlcs,description,screenshots,videos,related_products,changelog GOGDB has the link on the 'Details' tab for any game. There, you can see under DLCs if and how many it has, and under 'Expanded DLCs' the product title.
For a long time I and other users wonder instead why in the GOG version, which has the same price as the Steam one, are missing these two other DLC that you mention, plus two others:
My Time At Portia's DLCs have also been asked several times and the developers have hardly ever responded. Could it be that GOG simply creates placeholders that it copies from Steam even though it will never sell certain DLCs?