I sorta doubt the end of school celebration thing is as applicable today as it was a few decades back. In the '50s and '60s, "gym shoes" were only for gym class. It was very uncool to wear them as daily wear. They had no class. Since the 70s, most kids wear athletic shoes all the time. There's no need to change shoes for gym class. The symbolic gesture of throwing one's ugly, smelly gym shoes (which one only owned because they were required for a despised required class) over a phone wire on the last day of class just isn't there any more.