Itch.io seems to have a lot of low pressure, possibly unranked game jams which exist primarily to get something out there and have the experience of completing something even if it is really messy. I feel a lot like Pornucopia in that a deadline makes it much easier to work on things. It also helps knowing that you probably work at the same time frame as someone and makes it feel more involvement with a community.
The game jams that have already happened here sound really great, but I think there should be informal jams too and if someone wants to use itch.io, it would probably be the best option. No need to pressure the owners here when it isn’t hard to try organizing your own. Plus you might attract some new people since Jams are displayed publicly (although a bit hard to sift through).