Cheer at my school was a sport. In the summer we had non mandatory practices, but they made it very clear at the parent meeting before tryouts that if you were in town, you were expected to be there. Camp was mandatory and could not be missed. There were two tryouts per year, one for football and the other for basketball/competition. This way if you were only interested in doing one that was possible, but 99% of people did both. Fortunately the school I went to is very supporting of cheer. We had a full 7 panel mat, and the school provided uniforms and warm ups from the athletic booster fund. I think that having a school that backs cheer makes all the difference. We were held to the same standards as any sports team by the school, but the coach held us to higher standards. What they do obviously worked since they placed 2nd at state this year and have gone to state every year since the school was built except for one.
ETA: In Illinois teams can have non mandatory practices all summer, but theres a no contact week where no teams can practice with a coach, but if the team wants to get together on their own and run drills or condition, they can.