There isn't going to be some magic lawsuit that fixes the age issue. The reality is every fall there are middle school football games with 200 lb kids playing against 100 lb kids and everything is insured.
Parents just need to do a little research into what they are signing up for and be realistic. Don't have your son play in a 2020 AA tournament if you don't want him going against a few 6 foot d-poles. Do you think you can go to Young Gunz and not see abnormally large and fast athletes? If your son hasn't gone through puberty you might not want him to play on a 2019 A team even if he was great when he was in sixth grade. There will be boys who are physically mature on that field.
The problem comes from parents not accepting that no matter how much time and money they have put into lacrosse, if your son isn't lightning fast or he didn't mature early he is at a disadvantage in middle school.
Maybe you should just let your son have fun on a less competitive team rather than whine about what other people are doing. The size issue exists regardless of whether it comes from early puberty or from holdbacks.
And no, I don't have a holdback. I do have a 2017 and a 2020 going through puberty at the same time so I have seen both sides of it. | 
