I love all the holdback parents coming on here and somehow because 2020 is now a 'high school' year, then everything is all right and even again. (Despite not one 2020 has played a game in HS yet). If your 16 year old freshman is playing varsity this year, then more power to him and that can be respected, but during the upcoming summer season, if he's on a 2020 team, he will be at times playing against younger competition. And for your ego I hope he dominates.
But if you think as parents we are sometimes nasty about the subject, then you should hear our kids talk about local kids who have all of a sudden repeated for 'lacrosse reasons'.
I also understand that if your son goes to a Prep school then its almost a prerequisite that he repeats, but this is where lacrosse, and it's antiquated grade based system of summer tournaments, etc. has allowed many to game the system. Lacrosse is the only sport that comes to mind where the stigma of playing down during the travel season is somehow defended.