On the contrary, they are probably work-hardened at the original point of deformation. Try annealing some of a batch and see if they don't dent more akin to original primers.
I did some tests with annealed cups -- it isn't without some gotchas -- if you overheat them, they explode into glowing fragments all over your workbench and being so small, they heat fast. I did manage to get it to the point where I wouldn't overheat them, but I don't see any real difference between annealed and not annealed primers post firing -- see pics here:
PM me an address i will ship you some 38s if need be. Appreciated, but I'm good -- I haven't been to the range in a month so making some empties sounds like a treat. ;-)