I've known about it for a while. It's pretty much useless to my knowledge. I've only seen kwiggle use it, at the end of matches where it will do enough to kill without doing a real juggle.
This exactly.
You could do a full juggle for extra style, but the point of the air throw is to have a reliable way to do 35 damage (42 in Lab and blue tiles in Danger Zone, though Danger Zone's free launch on knockdown and ease of stage falls limits its use there) at the end of juggles. I do it right after a launch too, usually after 236T and 33K, but only if one the following situations occur:
1. Opponent has 35 health or less.
2. I'm lagging online and teleport cancels aren't working.