I'm not convinced it has a net benefit. People who update on the day will be already surprised. People who update later will have forgotten all about the background of a webpage/tweets they already saw.
By the time 6.1.1 it'll be forgotten we'll restart a discussion that would have otherwise completely faded away and mess users about in the process. --- Someone on chat proposed putting a link to the wallpaper in the announcement, that would look the most deliberate. "Our page today featured the artwork of our contest winner blah blah blah, with Plasma you can make your desktop your way blah blah blah, download their wallpaper here.". David
