Currently, it is hidden when not viewed via the editor. Just don't interpret it if it's problematic.
https://addons.mozilla.org/en-GB/firefox/addon/enhancer-for-youtube/reviews/1934841/
Per http://reddit.com/comments/2zr4y7 and http://reddit.com/comments/ypcsot, I'd like to be able to sort entries of playlists, especially chronologically. Considering that finding all iterations of `<span dir="auto" class="style-scope yt-formatted-string">1 year ago</span>` should be all that's necessary, I believe that this suggestion is reasonable. I wish that an issue tracker were available for such requests.