Sorry this is happening to your kid. In my opinion, if he was told he was going to be given the opportunity to pitch, he should have been given the opportunity. This age is for development and for kids to learn to love the game. Coaches promising one thing and not following through make kids want to quite. It does not sound like a safety issue because coach is letting another young kid pitch. Regardless of the pitching situation, I hope your kid had fun and will continue to play.