05/16/2016 (Mon) 06:49:28
For me the problem with gifs is only the size. So I think a reasonable thing to do would be to put a limit on the size of animated thumbnails. If the scaled gif would be larger than a given threshold then just use a static thumbnail instead. Otherwise, animated thumbnails are fine.
A good thing about animated thumbnails is that they prevent hiding "potentially-unpleasant" content behind a beguiling cover.