Gregory's Server
If you look at the schedule for a past FediForum, such as https://fediforum.org/2023-03/ , after the demo hour, you see it says "Collaborative agenda creation: bring your session proposals!". That's when the agenda is made.
Before then, nobody knew what was going to happen the rest of the day: the schedule grid was empty. During agenda creation, people who want to run a session fill it in.
For a field like the Fediverse in which community and collaborative problem-solving is really important, (and not Listening To The Expert) we have learned over many years that unconferences tend to work much better, so that's what we do at FediForum.