The point is that the teacher recorded by the two girls in Rye was prepared to validate such a hypothetical identity; that she insisted there are three sexes and that she called the girls "despicable" for having a grasp on reality. Regardless of whether there are hordes of children cosplaying as furries, this teacher's reaction shows that batshit ideally can and has taken hold in schools. That's the point the Guardian article also misses (deliberately, I'd say, given their complete capitulation to identity politics).
Yeah, this is a good point. I think that the teacher is extremely confused. She also seems to think that it's homophobic to not affirm trans folk. And I actually agree with you that it is a problem to have such uninformed educators wielding so much power.
But I still do think that it does matter whether there are lots of children who are identifying as animals. If there are, then of course we have a big cultural problem. If there are not but we're reporting that there are, then we run the risk of making this reality come true. Furries do not identify as animals. There are a few role playing furry children. When we report stuff like this, we put it into kids' heads that they perhaps should identify as animals. And we also end up stigmitising and marginalising furry kids, who are already very vulnerable kids.