I've seen this happen, the worst was actually a non-dad coach (young guy trying to be tough, or toughen up the players or something). Families quit because of it, I don't remember whether they got any money back. I agree that the organization should be clear to its coaches up front about how they should play players, and how to communicate that to the families, but in our 5 years, almost no coach ever did this. Certainly there was never anything in the contract about playing time.
It's good that the travel organization head specifically told you to contact him if this happens; you should definitely do that, so you can make a decision quickly. Sometimes they don't pay attention to what their coaches are doing until the season is advanced, unless a parent complains, especially if it's a large organization.
Did your son enjoy the winter practices and the team, before this weekend?
Player talking to the coach first is always the advice for high school where, as cabbagedad noted, the best play. This is something different, it's as much about the time and money to travel, hotels, etc. as it is about the team fees and playing time. That is your business, not your son's.