I've never actually experienced that myself (featured back to submit) though I suppose if I dig back far enough it may have happened. Like all people I imagine the moderators have their quirks. Strangely enough today I found that I had been reduced to two allowed submissions from three, probably because my output this week was more sparse. Or maybe somebody flagged one of my memes or comments for some odd reason.
I find demotivationals helpful when I'm lacking inspiration. You can pretty much plug in any silly photo and make something funny out of it.