Im wondering this as well if they would just send you the newer fender or if they actually have a different fender for the older models.
Im in the same boat as the OP, Im about to order some new rear fender. OEM at the dealer would actually be cheaper than Maier for me in Canada. I think im just gonna get the oldest model I can get in my color and hope that they dont have warning plate. unless somebody can chime in on this and confirm if they would have warning plate or not.