I read in a post here-----and I recall thinking that it seemed to be a reliable comment, that K. Zildjian never drilled cymbals, so if you have seen one then it must be an aftermarket modification.
The problem with some rivets, is they are much harder than the cymbal and they ream the holes out very quickly. I played those small headed rivets ,in the 60's----until they all fell out. It turns out, I needed larger headed rivets to replace them. Ever heard of keyholed rivet holes?
The only experience, I have with factory installed rivets, is an N.O.S. 60's A. Zildjian 16". It has brass rivets. I would assume, the idea was for the rivet to wear, not the cymbal.