Gosu development is going very, very slow currently. There is also not a lot of low-hanging fruit left after almost 20 years of development.
As far as Gosu games are concerned, there was another Gosu Game Jam last April with 7 entrants:
https://itch.io/jam/gosu-game-jam-4 - but all the talk around these jams happens on Discord, and none of the jams have been mentioned here.
I guess most people these days are used to Discord, instead of tiny forums like this one with their own account system and so on.
Edit: Added a sticky topic to point this out.