Shedding the right to freedom of speech at the schoolhouse gate

The famous quote from Tinker v. Des Moines Independent Community School
District (1968) should be applicable, but it's not.

[Students] do not shed their constitutional rights to freedom of
speech or expression at the schoolhouse gate.

Liam Morrison, a seventh grader at Nichols Middle School in Middleboro
Massachusetts, was ordered by his principal to remove his t-shirt, which
stated "There are only two genders."

Note: It's two SEXES. Even the kid bought into biological versus social
transgender jargon of sex versus gender.

He complied.

Being a wiseass, he next wore a shirt, "There are CENSORED genders."

The second time, he didn't remove the shirt, so he was kicked out of
school for the rest of the day.

During Pride Month celebrations, the school celebrates that there are an
unlimited number of genders.

The kid filed suit in US District Court; he lost at trial. The school's
argument, that there are "real" mental health concerns and trivializes
the significant harm that could occur to nonbinary students captive in
the classroom looking at it.

He lost again at First Circuit.

https://www.ca1.uscourts.gov/sites/ca1/files/opnfiles/23-1535P-01A.pdf

I don't understand how this isn't a slam dunk under Tinker for the kid.
They're appealing to the Supreme Court.

https://www.bostonherald.com/2024/02/07/massachusetts-student-who-was-banned-from-wearing-only-two-genders-shirt-is-focus-of-free-speech-appeals-case/

https://www.bostonherald.com/2024/02/08/massachusetts-middle-schoolers-case-about-only-two-genders-shirt-goes-in-front-of-federal-appeals-court/

https://www.bostonherald.com/2024/06/10/massachusetts-middle-schooler-banned-from-wearing-only-two-genders-shirt-loses-federal-appeals-case/