Of course it helps.
The mask helps to prevent an infected young player (*who is showing no symptoms*) from coughing, sneezing, spitting, or simply expelling droplets (talking/shouting) near other people and infecting them, thus spreading the virus.
I agree that it does little to protect the person wearing the mask.
So we should put our own child at risk? A properly fitted and sanitized mask works. A dirty rag stuffed over a kids face is unhealthy. There is no evidence you can present that would change my mind on this. Some rules put people at risk and should be modified on a situational basis. This is one of those times.
Risk? More risk driving to the rink. Two week report 7/26-8/8 of MA death rate by age group... average age 86. https://www.bostonherald.com/wp-content/uploads/2020/08/WEEKLY-covid-19-dashboard-8-12-2020.pdf