Not sure if the list is supposed to only be accounts that moved from another service to the Fediverse completely, but some other notable accounts/organizations on the Fediverse that I can think of off the top of my head:
Neil Gaiman is also on mastodon (and it wouldn't surprise me if some of the other authors in his cohort are too) though his main social media for major interactions is still Tumblr (which depending on your opinion of the Good Omens fandom, is either a blessing or a curse)
And Jeri Ryan, both of which are rather active too, which is more than many tech people who crept over to Twitter can say because they have more of a following there.
So I click the link. It opens in a webview. I see @stephenfry@mastodonapp.uk there so copy it. I go back out of the webview so I can see my search button. I paste that link in there. "This sub has no posts...retry"
Am I doing it wrong? Or is this just a godawful UX?