The problem isn't the visual marker on his profile; It's that he shows up as a valid contributor to this wiki (including on lists such as Special:ListUsers), and if he ever returns (or someone hacks his account), they have bureaucrat rights despite having no personal right to have them.
At best him having that right results in nothing. At worst, there's an account that could make everyone on this wiki a bureaucrat, delete every page, and block everyone (including me, though I could unblock myself). At medium there's an account that by permissions has as much as say in wiki as any valued member of the community and then some, just because they clicked the "make a wiki" button and edited the front page once.
This message is more to prove to Wikia that he is not an active member of the wiki, and no one is 100% against it since I'm trying to remove someone I disagree with or something. It's a fairly common request to request from Wikia, and requiring a public post a week before the request is a safe guard.
Edit: Leaving an inactive admin/bureaucrat that has given to a community and is trusted is one thing. But leaving someone with no right to represent the wiki isn't a great thing. Making a request to wikia is the proper way to do this (versus hiding his status despite having it), and is not hard (I just make my request and link to this).