I'd agree with the above answer as being a better explanation
My 7 year old does gymnastics. They touch them all the time ie helping with forward rolls, bridge, handstands, bar work. Can you see them practising? Or other groups?I’m sure if your child said no or didn’t want to do it they would respect that. They are probably applying some pressure but not enough to hurt. She’s not done the splits yet but they are practising the stretches involved.
When I was dancing as a teenager we were taught a couple of assisted stretching techniques which were amazingly beneficial, not forcing to the point of pain, but improves flexibility much more than independent stretching. For example, someone lifts your leg as high as it will go, you then push back against them with all your strength and they lift your leg again and it will go further. I’m not familiar with gymnastics but I imagine it will be similar x