I noticed there were fewer stickies in the Reading Recommendations forum, but for the life of me, I couldn't tell you what's been unstuck (well, except for the 2015 Challenge List thread, which I did
). I'm sure you're right, though. And if it turns out people really want it stuck again, it can be.
Generally speaking, though, and not making a judgment on any particular thread, I think it's good to shake up the stickies other than the most pertinent and vital. Contrary to the intent, I know I get to the point where I don't see them anymore. Hence my inability to recall what's gone.