I notice that some of my follow users on my wiki's about me page is gone and replaced with this phrase "This user has not filled out their profile page yet." what exactly happened here? I know for a certainty that they use to have stuff up there
This is a bug that Fandom is aware of, and it's being investigated. It should be fixed soon.
https://community.fandom.com/f/p/4400000000002812770