That's how it used to be done on any bike.
I don't know if there's anything special or unusual about the current crop of anodized fg/ss rims, but I have used a practically new '85 Schwinn, a 2001 Raleigh which had nonmachined rims, a rim on a c/b cruiser I added a brake to, and am about to start a NOS Gitane criterium. All of those bikes had an as-anodized finish on the brake track.
It's for looks. The wear doesn't look even unless it occurs on an equally shiny machined surface.