Girls had the option of wearing a skirt but, in my time, no one ever did. In winter, we were allowed to wear white skivvies under our polo shirts and could layer up with a scarf in a matching colour to keep warm.
And, you know what? The world didn't end. I'm not aware of a single person who ever questioned their gender identity because we all wore the same clothes.
The uniforms had nothing to do with our sexuality or transgenderism like some pundits are losing their heads about (although I wouldn't have a problem with this), we all just chose to wear what we were comfortable in.
I can remember going on school trips out of town and laughing with my school friends at the poor girls wearing those horrid long plaid skirts.
Why does it matter whether boys and girls are wearing skirts or shorts? It won't affect their learning in any way, and that is, after all, why they're at school.
Bring on the change.