BUR #6598 has been approved by @evazion.
remove implication non-repeating_gif -> animated_gif
create alias non-repeating_gif -> non-repeating_animation
In topic #16008, non-looping animation was turned into non-repeating gif because it was thought that only gif could be non-repeating. However we have a few examples of non-repeating animated png in thumbnail_surprise animated_png.
So unless we want a non-repeating png tag, the implication needs to be removed.
Updated