COMPLETELY Agree this this! I was in a very, similar situation last year and something crazy/unexpected happened mid-season at a gym that i had gone to for years (and loved) and I had to leave mid-season. And I know for a fact that If I would have had to get a release form from the coach of the gym I had to leave she would have been very bitter and not given it to me. I just do not think this rule is fair. Does any other sport make you get permission from your old coach to play for another team? No! And Yes sure, I know people are going to say "it teaches kids about commitment" but, if they are in a bad situation (and yes things can happen at a gym mid-season AFTER summer is over), why would you them through that misery?
I agree with you about bad things happening mid season - at that point the USASF should be contacted and they should be able to easily see that you should be released and handle it!