Funny you posted this question. One of my sons is in his first year as HC in a prominent summer league. Through him, I am getting some interesting insight into the dynamics and workings of those teams and leagues. I was actually going to get a thread started to see what different players are experiencing in various places and with different summer teams around the country.
With summer college ball, perhaps more so than any other level, there are some seriously contrasting perspectives. The college coaches are sending their players to play and get better, so they all expect their players to play when agreeing to send them. The owners are trying to put a winning product on the field to sell tickets and sponsorship, so they want the coaches to put the best players on the field all the time and they want the players to give their all out best to win. The better players (typically those who played the most during the college season) are worn out physically and mentally and many need a break, at least to the extent that they don't want to play in a game every night for several consecutive nights. Parents often travel a good distance just for a few days in hopes of seeing their kid play. The summer coaches are often largely caught in the middle of all this. Some were involved in bringing players on board and some were not. Some were partially involved and know what playing time discussions took place and some were not. They have to try to make everyone happy (impossible with the conflicting agendas) and keep players motivated to play well all the way through the summer season. They have to try to motivate them to want to earn a playoff berth for the right to spend yet more time away from home without rest and without seeing family with what little time they have left of their summer before they have to head back to school and start the grind all over again. Most of the summer college coaches are also regular college coaches/asst coaches and have those relationships and reputation to protect.
Further complicating the whole equation are things like formal contracts, injuries, home sickness, work requirements, summer school, host family experiences, pitcher inning limitations, etc., etc. Also, college coaches will often leverage sending a good player with the agreement that the summer organization will also take a few "other" players. It can become quite the tangled web.
So, bringing this back to your particular scenario, somebaseballdad, I think a key is first knowing how your son came about being part of this particular team/league. Did his college coach refer him or did he make his own arrangements? The answer will factor in to determining the best course of action.