On the home tab, there is the recently published boards widget in the lower right of the page.
I accidentally retired a board I didn't mean to, and then restored it. When I visited the home tab, I noticed that my board was at the top of the list again. This seems like a loophole someone like Smor might abuse to keep a map always on the front. I suggest that restored, reversioned or copied maps don't go back to the top of the list.