And HTTP/2 can be used to provide video steaming, but that doesn’t mean that nginx will be the next YouTube. This isn’t a question of technical feasibility, but project focus. Though, I must admit, I don’t follow the development of fediverse software all that closely, so maybe it is on the roadmap.

I think it’s unlikely that Mastodon (or other federated short form blogging platforms e.g. Pelorama) will integrate live-streaming as it’s pretty far outside of the normal content they are built for. There is a project that does support live streaming and is federated though: Peertube https://joinpeertube.org/