But the debate here is so far off into the weeds that most high school administrators who might tell the teacher to stop won't understand the distinction, much less care enough about it to tell the teacher to stop.non-standard doesn't make something empirical or not
I've worked with a lot of faculty through the years who have weird pet theories or alternate views that they enjoy spending a small amount of class time on over the course of the semester or year. If their students are otherwise learning the Physics they need to know, no one has ever been inclined to tell them to stop. Most high schools in the US only have 1 or 2 Physics teachers. It's not like there is a knowledgable administrator to appreciate the distinctions and set boundaries.
But zooming out more broadly to high school science in general, I know there are a lot of things that are discussed as hypotheses. By definition, hypotheses are somewhat lacking in empirical support, yet I wouldn't fault a biology class for spending some time discussing the RNA world hypothesis or an earth science class for spending time talking about the nebular hypothesis.
The ether was a non-empirical hypothesis in Physics that still receives (in my opinion) a disproportional amount of (favorable) discussion in some high school Physics classes. But I think this should be permissible as academic freedom.