The linked form no longer accepts answers, and the user that managed this project (Template:FlowMention) is no longer active on the wiki. It could be moved under the Nonbinary Wiki: namespace, as some guidelines to get involved. But the table should probably be removed, since we already have Notable nonbinary people. Let me know your thoughts!
Topic on Nonbinary Wiki talk:Celebrity pronoun project
My understanding is that the Celeb Pronoun Project was meant to apply to all celebrities, not just nonbinary ones? So it's not just a duplicate of notable nonbinary people. But yeah, it is a little useless if it's no longer being managed properly...