If glider racing were an athletic endeavor like gymnastics or football then it would not seem inappropriate or out of the ordinary to recieve real time advice from others during competition.

But glider racing is a thinking endeavor, more like chess. It certainly isn't reasonable or acceptable for chess players to receive advise from others about how to get out of a predicament. Why is it reasonable for glider racers to get outside advise about what would be the best next move?

Only the brain(s) onboard should participate during actual competition. The US has it right in this case and should not yield to a bad idea even if others have.