I can scratch the black off mine with a fingernail, so I seriously doubt its power coated. My guess would be that Speedymoto does this because the pegs will see the most wear, and they can be touched up.
You cannot re-anodyze a part without first stripping off the old anodization (typically an acid bath). The same can be said of powder coating, you really don't want to put a new coating over an old worn out coating, it will not cling as well. So all of that said, it makes sense to just paint them.
No matter how you coat the pegs, they will eventually wear though to the base silver, painting them, they will wear out faster, but touch up only takes a rattle can of flat black. I asked the question just to make sure Speedymoto didn't do something different just to get these sets out the door.