Characters are definitely not removed.
The message about the admins making it public seems very weird. I would get rid of that, and can not use this site for many games that have any child-safety restrictions (teaching in schools for instance) because of phrases like this.
The fact that it is not final anymore means we don't really need much more than a "Are you sure you want to retire this game? It will be moved to the Retired Games drawer at the bottom of you
game list. You can come back here and unretire it later if needed."