When attending PyCon US this year, I thought it would be neat to have a central forum where people could discuss the event, coordinate meetups and plans, promote talks with a greater focus on who might want to attend them, and in general just talk among themselves. It would be especially nice for first-time attendees who might not know anyone in the community.
I think asynchronous forums are strictly better than something like discord for this, and since we are already using discourse it is a natural choice. You could even fork off a pycon-discuss.python.org to keep it self-contained, and tie the login to pycon registration.
The down side of course is that someone would need to moderate said forum, but I’m sure we could find volunteers to spread the load around (and yes, I would sign up if needed - I’m not just volunteering someone else’s time and energy, though I’m sure there are people who are far better qualified to do it!)