Agree. Completely different disciplines. There is acro-dance. Probably what they mean.
Uses acrobatic tricks in the choreography. Not gymnastics. At. All.
It’s not a gymnastics floor routine. Which has prescribed movements in certain sequences.
Often confused. I think.
Apologies. I should have written “team sports.” They all did some gymnastics/tumbling programs from the time they were toddlers. The youngest kept it up for some time, and was working on apparatus, but was never on a competitive team.
We were happy they preferred activities which did not require that we give up all of our weekends for games at various times, as soccer or baseball could.
My eldest used to argue that marching band ought to be considered a sport! 
My youngest has been in competitive dance for the last 5 years. From August to April of every year she practices 20 hours a week, mostly in the evenings after school. From January through April she participates in weekend dance comptetitions normally 3 weekends a month. And about 20% of these competitions are far away, Nevada and California. It is definitely a team sport. And it is not cheap, with the cost of group lessons, private lessons, costumes, competition fees, travel costs, etc.
The team she is on brings in outside choreographers for specialized lessons, etc. It is highly competitive, to just get on the team. And the whole “dance mom” thing is real.
We have made sure that our daughter fully understands that we are doing this only because she enjoys it. She is under no illusion that she’s going to end up on Broadway or in Hollywood.
Ca. 1980 when I was in high school, marching band DID count as gym class.