A comment by the EFF: "People coming from Twitter tend to think of the fediverse as a Twitter-replacement [...] but that’s only a fraction of its potential. The question isn’t if the fediverse can replace Twitter ... With enough momentum the fediverse can be the fabric of the social web, incorporating existing systems like Tumblr and Medium and outright replacing stragglers."
Register an account and click “Make a contribution” (although you don’t). You should receive an email confirming that you successfully booked a ticket. (The only thing I don’t understand is that a site like opencollective.com is using Cloudflare if I may say so.)
There is not (yet) a program for tge event unfortunately.