While I would agree that this should NEVER have gotten to THIS point, I can't help but ask:
A THIRD set of tryouts? And THEN cut kids?
In most high school varsity basketball situations, coaches KNOW they'll be adding FB players, and hold roster spots. They cut to a certain number, accounting for additions. If -- BIG IF -- they hold extra kids until a third cut, they do so with the clear understanding of ALL involved that it's for PRACTICE PURPOSES ONLY, and that ACTIVE ROSTER SPOTS ARE NOT GUARANTEED UNTIL A CERTAIN DATE.
Sounds like a complete lack of communication to me. Not unconstitutional; just stupid.