I'm planning on updating some of the UI elements at some point,
I worked on most of it when I was still very new to editing software and animating, so I'll be revisiting them in the future.
The hairstyle changes are character choices, and some will have new styles now and then, but that doesn't mean they won't return to the original.
I don't want to get into noticing style changes with the LI's between the 7 main girls, as I think it will become annoying for everyone if you have to mention it everytime, for example, Iris has already had 3 different hairstyles between 0.1 and 0.2.
Unless the change is something significant, like Siri wearing a dress.