I realize contra dancing is very important to you but, again, school have no mandate to instill a love of contra dancing into students.
They do have a mandate to get the kids moving and maybe even to teach them that physical activity can be fun. Since you love dance so much, it's natural for you to think that it's a perfect activity for this mandate. But, at the point in their emotional development that most high school students are at, this kind of of social dance is actually kind of an iffy thing to teach a love of physical activity, as others have pointed out from their own experiences. It's not a coincidence that most contra dance groups do not have a lot of high school students in them.
I think my kid's high school is on the right track with having the kids run and with having them make up a solo dance to modern music of their own choice rather than teaching them square or contra dancing. And I say this as someone who loves both (and ballroom too). But not many High School students are ready for this sort of interaction or going to appreciate it being forced on them and you don't get people to love stuff by forcing it on them when they aren't ready.