From the Foundation for Individual Rights and Expression (Carrie Robison & Aaron Terr); if the facts are as described (and I've generally found FIRE's accounts to be trustworthy), this does seem like a clear violation of the First Amendment:
New Jersey law requires all school boards in the state to set aside a portion of their meetings for public comment. During the Teaneck Board of Education's Oct. 18 board meeting, many constituents voiced opinions about a recent letter from the district's superintendent to students' families following the events of October 7. In the letter, Superintendent Andre Spencer acknowledged the "latest incidents in the cycle of violence in the Middle East." Spencer recommended that schools "foster an open dialogue" and called for "a comprehensive understanding of the complex factors impacting our world."
Several parents and community members used the public comment period to criticize Spencer for not explicitly and forcefully condemning the attack. But when they described Hamas's actions to support that criticism, the board repeatedly shut them down. The board took particular exception to commenters' "graphic" descriptions of the attack and repeatedly told speakers to keep in mind that children were in the audience.
Yet when other commenters used their time to emphasize the plight of Palestinians and used similarly "graphic" language, the board allowed them to continue.
For example, when one speaker said it's possible to unequivocally condemn Hamas's actions without taking a side in the conflict "unless of course you're trying to appease people who actually think that the raping and murdering and pillaging of the community is appropriate," Board Vice President Victoria Fisher immediately cut him off. In contrast, the board remained silent when another commenter said, "These people talking about raping and piling bodies on top of each other, that happened in the Holocaust. And if they're having PTSD for what they're doing to the Muslim community in Palestine, that's something they need to seek mental health counseling for."