My father was the AFJROTC instructor at Holy Cross High School in New Orleans from '66 til '72. He was the first hired for the start of the Junior Air Force ROTC program in Louisiana.
I was in New Orleans in 1964 and do not remember that. My father was in St Tammany parish, a school principal in the thirties and lost his job because of huey long and after that teacher tenure was enacted sometime in the forties or fifties. No teacheer lost jobs for exercising free speech. But teachers didn't get quoted in the paper on these things, they were usually smart enough not to.
I think you are not telling the truth.