I suppose some other shopper would be offended to have a man in the dressing room. Although for me, I would think it's obvious Jack would not be your average male in a dressing room. To me, it's no different than mother's with their young boys in women's dressing rooms - sometimes you have no choice.
I did write Macy's from the link you provided.
It's all okay for a surgically altered male to enter the Miss Universe contest, but not okay for a handicap gentleman to be inside a ladies private dressing room?

Who makes these rules?