Oooh, I think I figured it out. Why the “Gnomeregan Infantry” in World of Warcraft lost their iconic helmets.
It was the Garrison Holiday decorations. Someone tried to reuse an existing NPC and mod them in to the Winter Helpers for the Winter’s Veil decorations. But, it was either unnecessary, or just couldn’t be made to work that way. Once the change was made, it was not reverted back. I can understand it might have been easier to remove the unit rather than fix it. But you can still see helmeted Gnomeregan Infantry with Winter’s Veil outfits pop-up in the Razlo Crushcog projections when you get the quest to kill him.
Anyway, I liked the helmet. I felt like it was really iconic to the unit and to gnomes in general. Wish it would come back.