What public school activities should a cyber school student be permitted to participate in?

A Pennsylvania Cyber Charter School student who lives north of Philadelphia is attending Neshaminy High School next year. He's attend schools in the Neshaminy District in the past and wants to go to the year-end eighth-grade dance. However, the school says no. Administrators say dances are social activities for current students. They argue that law allows home-schooled and cyber-school students to participate in public school academic and co-curricular exercises, such as sports and music, but not social activites, such as dances.
What do you think?