Hi
Hope you are still happy with your jacket.I believe the loop is for attaching the jacket to a pair of pants just in case the zipper does not fit. Unfortunately the zippers are not universal between companies. I have a Rev'it jacket that will zip to my Olympia pants but my Spidi leather jacket will not, so I use the loop.
And ditto to shaking my fist at womens sizing, ESPECIALLY with motorcycle gear.