I've gone back and forth on this. It's maybe easier for me to be okay with a policy requiring shorts because two years ago, when my seven year old daughter came to me in tears because she didn't want to have to compete without her shorts on, I gave her what I thought to be the only two choices she had - either take off her shorts or don't compete. This was when I was a new gymnastics mom - I really didn't know very much about the sport. I had never heard of giants, or mobility scores, or closed door practices, or Larry Nassar. All I knew was that the uniform to compete as a gymnast was the team leo. I can tell you all that, with the benefit of this forum, 2 years of experience, and my own growth as a mom and a person, I feel a great deal of shame that I didn't try to fight for my daughter's right to cover her body if she wanted to. So, I obviously have a kid who is more comfortable in shorts or pants and it's easy for me to applaud any rule that allows her to wear them.
I also think
@Geoffrey Taucer stated the other side of the debate very clearly and eloquently - the point is to allow gymnasts autonomy over their bodies, and requiring them to cover their legs is just as much of an example of controlling their bodies as requiring them not to. So I also agree with most of the people here arguing against the new recommendation; seriously, I'd love to get together with you all to discuss the dress codes in my children's middle school which make me see red every time I see a different rule for girls so that they aren't a "distraction."
However, something I keep getting stuck on is that we are talking about a uniform, which, basically by definition, is required clothing for a collection of people belonging to the same group. Every sport in which my children have ever participated has had a required uniform. For soccer it was a pair of super ugly and uncomfortable blue shorts and a team shirt (plus shin guards, soccer socks, and appropriate footwear), for basketball it was an equally hot and uncomfortable pair of black shorts and a team shirt (plus appropriate socks and footwear). I've heard of gymnastics teams which require the purchase of several leos each year. Team members are required to wear a special practice leo on Fridays, and another team leo during performances, and maybe even another leo for meets. This year for states, the state of NM provided leos to every athlete for the state competition and required every girl in every level at every session to wear these new leos (which seemed to fit poorly, pull in uncomfortable places, and literally caused my daughter's skin to bleed where a seam rubbed under her arm for the length of the session.) I know from reading posts on this forum that many gyms have a required hair style for gymnasts - and not just for meets but also for practices.
In each of these examples, the requirement of ANY uniform is, in some way, taking some bodily autonomy over the athletes. Let's be honest - how many of us have seen team girls try on their competition leos for the first time in the spring and then compare notes about whether it was more itchy and uncomfortable than the previous year? The difference between asking an athlete to wear a uniform that might feel too hot or too itchy and asking an athlete to wear a uniform that makes them feel too naked is real and it's significant.