It should be noted that officially, Fandom staff don't request admins to do anything about it, neither block or report. However, admins are free to block for almost any reason they want.
Just FYI, 13 is not the only age you need to be aware of if you are concerned about underaged users. Anyone in a country that is a member of the European Economic Area (essentially the European Union) or the US state of California needs to be 16 or older.