The streaming is public and free, only the chat is sold out. So you can still watch (now or later).

Nice. Just now watching their livestream and having organized a small conference via zoom, i wonder if there are easy ways to do this broadcasting studio stuff easily (picture in picture and stuff) with an easy interface for the interviewees (idealy a webrtc web client)

Lmgtfy :) Just found this to answer my own question. https://obs.ninja/

Yep, OBS FTW! Donate!