It was said that the Hrothgar would have new hairstyles unique to them in the future.
I think the idea that their 'Hair' is just their manes/Fur is a solid idea on concept, because while you probly could make a few Hairstyles in game work, others wont work because of the muzzle and headshape, so their Hairstyles are made with the headshapes in mind.
I think this is more then fine honestly, it will make the Hrothgar stand out just a little more if they get their own hairstyles soon here maybe in the next expansion. I would love to see some longer styles with some braids. Maybe some unkempt styles as that would fit their beastal nature.