More specifically, they added eyebrows to one Hrothgar face (grumble grumble) but all faces did get something new, so it's definitely possible to give Highlanders eyebrows at this point, specially with the upcoming graphical upgrade. My guess on why Derplander's stubble had to be a separate face altogether is because there was already beard options in their facial features tab and they couldn't stack.
All in all, the devs really need to step it up now that even WoW's character creator is looking good, and it's (was?) "the worst one" out of the big mmos in the market.
