Mostly agree with you.
Thomas Jones is probably going to need one of those forms before anyone can call him Tommy though.
Not worth outrage, but I think the "school emergency situation" justification is a bit bogus. If he needs to be identified or found, the school and the family are going to know and be able to tell the police or others the nicknames he goes by. It was never a problem with my kids who all go by common nicknames for their given names....and had been from the day they were born. If it was truly a safety/identification issue, the school could make a record of expressed preferred names/aliases without a form requiring the parent endorse the same.
At the same, Florida has a law that specifically says teachers and administrators are under no obligation to refer to students by pronouns other than those assigned at birth . This law doesn't REQUIRE teachers and administrators to refer to students by nicknames or any other name other than their legal name. IMO, this law is pretty squarely directed at getting a record of parents that authorize a trans student to identify/use a trans name. Given other statutes in Florida regarding criminalizing gender-affirming care, it does cause me some concern....not outrage, but concern.