User blog comment:Rappy 4187/Technical Update: November 30, 2015/@comment-24545405-20151201193849

Your infobox banner is obnoxious and annoying, as well as broken. The wiki I'm an admin on DID switch to portable infoboxes sometime ago, and we're getting the banner. Granted, not every infobox was switched, but the ones that we use were.

The banner shouldn't appear if a non-portable infobox isn't used on any articles. I'm sure there are some small wikis, who don't have any infoboxes on their pages, scratching their heads, wondering what wikia is talking about.