Once it is back you'll notice that it hardly makes a difference.
Hardly. I need to find a forum and I can't because it doesn't appear on the list, even if I click on "all 759 forums". So once it's back I will very much notice it.
Google search term: gog.com forum name-of-the-game
Alternatively, if you own the game, go to your Library, click on the game, select More -> Forum