I would think the only kid who doesn’t make the freshman team and goes on to make varsity is a real late blooming pitcher who comes up with velocity.
If a kid can’t swing the bat well enough to make the freshman team chances are he doesn’t develop a varsity quality swing later.
Lorenzo Cain is an exception. But he was an untapped potential world class athlete. Cain wasn’t cut in high school. He picked up baseball in high school. He was way behind the baseball skill curve when he started playing.
At our high school it was rare for a kid on the freshman team to ever make varsity. Most kids had it figured out by high school and moved on. The best freshmen played JV. Some kids who didn’t make the middle school team played for the freshman team. They were typically LL juniors kids where freshman ball wasn’t overwhelming for them.
One of my 16u travel kids went to a high school that made freshmen play for the freshman team. His father told me it was brutal to watch. When my son was a freshman I thought JV ball was hard to,watch.