I'd expect at least the authors who do talks about the Fediverse to be here: Cory Doctorow... Marc-Uwe Kling... There are some webcomic authors as well. And we have some journalists. Heise Online comes to mind, they have their own Peertube instance. Then some other known activists, bloggers... And some people share drawings, fanart etc, not sure if that counts.

Edit: I forgot George Takei, and several other people.
Here's some list of noteworthy accounts including some celebrities: https://joinfediverse.wiki/Notable_Fediverse_accounts