He is stating since the rims are not chrome but that of satin or polished in contrast to the chrome window trim. I see what he is talking about because rims and chrome trim are opposite of one another. So he is envisioning blacking out the chrome trim vs powder coating the rims completely black. Cost factor would be easier to paint the trim vs powder coat.
I personally would not do anything to it, and if you must then powder coat the whole rim black and leave the chrome trim there as a contrast separator of the body lines.