Hoping For A Footnote's Fate

I wrote in December that the Supreme Court had some really interesting cases on its docket this year.  Following up on the lead story from back then, I note that today, a badly-fractured decision upheld the ability of a high school to punish a student for an inanely offensive banner at an off-campus event.  The most bizarre opinion was Alito’s; Justice Alito concerned himself with whether the content of the banner was political or social commentary which the student testified it was not; he did it as a joke.  But since when are jokes, even somewhat incoherently formulated, nonsensical jokes like this one, entitled to less free speech protection than political commentary?  I hope that Justice Thomas’ understanding of the holding as very narrow in scope prevails and this case becomes a curious footnote in the arena of free speech jurisprudence.