I have 3 undead, and I am always for more customizations!
I think all races should get straight backs if they don’t have them, undead, worgen, trolls.
I would have loved some wispy or partial facial hair options. In my opinion even some of the head hair options are too thick, they should be thinner, like a lot of the hair has fallen out, same should go for beards IF we ever get any.
Two of my undead are keeping the bones showing because of my rp thoughts for them, one will go no bones as to show his gear better, but I have always thought there should be more options, a skeletal hand, one missing eye, full skull head or skeleton body etc. I think undead and mechagnomes especially should have the one limb at a time, half face, partial bone or mech changes, it just makes sense…to me anyway.
Not gonna lie, I was expecting more for the Forsaken.
Yeah, the skin tones, hairstyle and eye options can add a lot of contrast BUT those are kind of “default”. Every race, across the board gets this.
So, after those options, what actual NEW things Forsaken get? Just the bone display. Yes, it is great and long overdue… But look at humans and night elves, and the amount of NEW (not “rearranged”) options they got.
What I wanted? Jewelry for girls, beard and moustache for men, new facial decaying options - have you seen the Maldraxxus NPCs with exposed brains, but covered by a glass dome?
Or wishfully thinking, even more drastic options like the so wanted straight back or being even more bone-y.
Nothing grows a on dead body besides bacteria and mold. Your biology teacher taught you wrong if you think it makes sense biologically. Dead is dead. Not : “This guy is dead , besides his hair follicles.”
Skin recedes quite dramatically after death giving nails and hair the appearance of some growth. You dont sprout a handlebar mustache and goatee in the grave. 
(But certainly could have one after death if you had one before) So I do support your wish.
That’s pretty neat actually. Like a version of what your spirit/soul resembles.
I think they’d gladly trade goofy eyebrow options and little stuff like that for something that literally changes how their silhouette looks.