I think what's far more important is the quality of the work that surrounds said "notches". I'd rather have a fabulous body and paint job without the notches than a mediocre one with them; I'd rather have a super paint-color change than a horrific re-spray where the paint color numbers match.
Yes, on a great paint and body work job where they were inadvertently left off by a paint and body guy more concerned with quality work than super-specific work to one model, they can be added without much fuss.
Even the best of paint jobs will eventually require a little touch up here and there. At that time, if you are missing them, have them put back.
I didn't go looking around for the % of cars at PUB with or without them, Jim--but it was someone else who pointed out the % of cars with and without the MB badge on the front bonnet/hood. Next time, Jim Huber, you get 15 cars together, in addition to the quest for notches--check for hood badges, too!