

You have a point. It was a joke to redirect the bull metaphor to a different animal, force of habit.
On the other hand, the term “pig” for Cops has become rather detached from the animal, just like Motherfucker doesn’t actually imply incestuous sexual relations.
But you have a point all the same.
Intersex is a biological rarity wherein a person exhibits sexual characteristics of both sexes. They’re neither strictly biologically male nor strictly female. Hence, if they’re supposed to use the bathroom matching their sex, they’ll need a separate bathroom.
(There’s a lot of complexity and unpleasantness I’m omitting for brevity, but the point is that they don’t fit into simple binary assumptions like the one underlying the headline)