This subject has been raised before re the XR....it's quite simple that all the grips left over from 2014/15 GS/Gsa, have now been fitted to the 2016 XR. You can bet when these run out of stock , they will be fitted with 2016 GSA grips, which are superb.
I agree to that all the grips can't be exchanged and retro fitted is aloud of bollocks too ..in fact I know it is