The Silent Age forum is still around. As for the original release announcement thread, I can't find it.

It was released in a batch with a couple of other games from the publisher, Meridian4. The game titles weren't mentioned in the title of the release post, which is probably why you had trouble finding it.

Edited to correct the second sentence to say what I actually meant.

Remember to search for and vote on any such site feature wishes that you can find in the appropriate section of the Community Wishlist. If you truly can't find any existing wishes that fit your idea after running various searches with different terms or combinations thereof, then obviously you should create your own wish[es]; however, there's likely at least one extant wish that would fit what you're asking for, at least for the idea in your second point. Here's the search results from a CW:Features search that has a couple wishes that might serve.
Also, if you want to promote any wishes (yours or others') for other people to vote on, I created a thread last week for just that purpose.

Lastly, not trying to dogpile, but I'll second Geronimo's sentiment that "thread" and "topic" mean the same thing in the context of internet forum structure, and are interchangeable; what you're referring to are game- and series-specific forums (or subforums, depending on how you want to think of this overall Community section's structure). : )

And here's the link:
https://www.gog.com/forum/general/3_games_from_meridian4_await_your_discovery_4b3fd

I see. Thank you both.