“chanting “Gay OK” after some students were removed “
At no point does the article say that this all started when the jack booted thugs came to break up a protest in the lunchroom. The protest seems to have started due to the 1st amendment infringement. And no “Gay OK” is not offensive, it is pretty much the definition of protected political speech.
A school is a tax supported institution. If they want to make a political statement, they can do it on their own dime. Would a Muslim calling for beheadings on his tee shirt be protected speech?