This is totally true. The Wisconsin Interscholastic Athletic Association, which rides herd over high school sports in the state, has declared that all negative chants at sporting events are hereby banned, lest someone’s feelings be hurt. Excerpt from the WIAA directive:
Any action directed at opposing teams or their spectators with the intent to taunt, disrespect, distract or enticve an unsporting behavior in a response is not acceptable sportsmanship. Student groups, school administrators and even managers should take immediate steps to correct this unsporting behavior.
Not sure about Wisconsin, but the opportunity to chant creative put-downs was the only reason I attended high school events … and that included school plays and student assemblies.