Its only more recently this feature hasn't worked, it was definitely working when the game launched as I remember it vividly.
The makeup copying only happened however if it was in CAS and it was the first time you opened the category e.g.
You create everday 1 makeup then open formal for the first time for a new sim in CAS then the Everday 1 makeup will be copied (or whatever Everday you had last opened before opening formal for the first time
I would actually prefer that certain features get copied to all outfits, not only hair. Like, if my sim wears certain little earrings, I want them to wear them in all outfits. So in each single outfit I have to zoom to the head, click the accessories, click the earrings, scroll to find them, choose the color and click. If they were transferred and I wouldn't want them, I'd just zoom on the head and click the little red cross on the accessory symbol. That would be way more intuitive and way less effort. I would also like to have makeup transferred, and I really don't understand why toddlers wear glasses in their sleep outfit, or why you can wear glasses to sleep at all, but not earrings...
Sadly this feature did exist, but its been broken for so long now it seems some people have forgotten its there.
