Looking at this forum a lot of the threads fall into these categories.
News threads get pushed down so that finding them all at a glance involves more effort.
Discussions in the general discussion forum are hindered and we are left with lot's of multipage threads going over similar subjects again and again.

It would make sense to have a new forum. One where the current news is copied to it and put as a sticky at the top for their duration, so people can see the current news quickly.
Along with that it could have giveaway and forum game threads like "one word at a time" , to fill out the new forum. Perhaps the larger threads can also get moved over there if they get into hundreds of pages.

Games that are about to be delisted could have their own sticky threads too so people can see it in time.

I think it would suffice with Forum Games getting its own sub-forum.
That's something that is entirely enclosed and encapsulated within itself.
It also takes up a lot of space and only has a few but frequent posters in them.

I could get by even with how it is now when I only checked the forum once a day, though I did have to go to page 2 in-frequently.

Not that any of this matters..I don't think GOG will change anything..
I hope to be proven wrong though ,)

Would fracture a already smaller user base, i know it sounds good on paper but in practice the active userbase isn't really big enough on here to support any major splitting

Maybe if the GOG forums were running on better software, it'd make more sense to do so, but not here.

It's just a new forum section which should be simple enough.

So would archiving old threads into the existing archive, yet there's plenty of them open and being dredged up by bots because they contain keywords that pop up in search crawls like "VPN" and similar.

You want to add another forum section? GOG have enough issues running the current ones let alone running more!