How, to send a private message, just click on the poster's name and a menu will appear, one of which is 'invite X to a private topic'. Perhaps there's a poster who uses the school-in-question's logo or has refered to that school in posts. If not, do a search on the school's name and team name to find parents who have talked about that school.
Starting a topic in the appropriate state or region's board at the bottom of the list of topics might also help. If you're concerned about putting too much info out there about your son, PM another webster for them to ask about that school.
There have been a number of threads here regarding JuCo's and your assessment of them is correct. In discussion with your son, remind him that he is eligible for the draft each June if he starts at a JuCo.
Google the school's team name, roster, players, however many ways you can think of to try to see how much variance in the roster there is from one year to the next to give you some clues to how many guys either are cut or who leave on their own. Check stats to see how much freshmen and sophs play. If your son is a position player, the stats will also tell you who (and what year) currently starts there. This info might ease your mind, or sharing it with your son might help balance his view.
The boys who go on to play in college dominated their hs teams, many dominated their travel teams as well. It's tough for them to remember that that is the case for pretty much all their new college teammates....including guys several years older and with those additional years experience.
And talking about this with our sons takes a lot of diplomacy, love, patience....and occasionally a sedative....each....