My apologies to you for the lateness of this reply.
There’s definitely a reason why “everyone” is gone from the GSB2 forums as well as its online challenges. (Note: online challenges for the original GSB1 are still active!) The official blog entry at this link describes the situation, albeit not in very much detail.
The developer has stopped all work on GSB2. Whether it might ever resume is highly unlikely.
I sincerely wish it were otherwise.
In other news, there’s still a tiny flicker of modder activity at GSB[size=115]1[/size]'s Gratuitous Modding sub-forum. It’s impressive that a few modders are still making at least a bit more new content, even though it’s strictly for the original game.
If you’re looking for anything at all that’s intruiging & different in the land of GSB, such folks are your best bet.
Good luck to you, grendelsven.