Realistically, I feel like bringing all the aesthetician hairstyles to viera is a more reasonable ask than completely new styles that could only be used on one race and one gender. Just my feeling on the matter.

As for the hats topic. It may be almost cliche at this point, but modders have done it. Able to turn hats on and off with the changing of a checkbox in the item metadata. Not all of them are gonna look right, with how viera ears float on the head, but a majority do. On top of that, they've also created hat compatible versions of base hairstyles.

So it's not impossible, it was just most likely work that was instead sacrificed at the alter of the MSQ. (In favor of the MSQ and other major features)