In my opinion, it is way too early to be making a documentary about Nostr. To make such a documentary now would be similar to making a documentary about the Internet back when there were no web browsers.
Prior to web browsers, the internet was little more than email, file-sharing, and Usenet. But after web browsers had been created, so many amazing things became possible. A similar kind of program has not yet been made for Nostr.
Moreover, building social media on Nostr is analagous to reviving Usenet to work on the Internet. Usenet was very flawed and lasted longer than it should have. Social media is worse.