With Covid, you are going to see an uptick of holding back across the board. You can’t just replace 2 years of schooling, that for some, was almost exclusively online.
And if you hold back for sports, who cares? The reality of athletics is stronger more mature bodies perform better, and coaches want players with college ready bodies. There are so many kids to pick from playing lacrosse now that they don’t have to take an on age skinny kid when they can take a year older kid who is more developed physically, faster and stronger with the same skill set. It’s a no brainer for college coaches. They want that college ready player and one easy way to get it is to hold back and give your body time to develop.
I think at this point in high school, after the top 15-20 players, there isn’t much separating players who have played on top teams at top tourneys/showcases. It’s more about what you bring physically to the table and how athletic you are and hopefully along the way you maintained a good GPA. When you get to 10th grade club lacrosse, nobody cares who wins these tourneys, it’s all about showing well individually in front of coaches and playing competitive lacrosse.
If the holdback route does not work for your son, there is always the women's swim team at Penn.