If pushrods ever become a marketing liability in the target demographic, they'll be gone like yesterday. I'm not sure engineering has much to do with such decisions.
I believe that's a very good point, I can recall when the four-valve hysteria on production cars began in the 80s, they all had these "16V DOHC" marking in the rear,
not that middle-class martin had a the vaguest what it meant, but it impressed the suburban neighbors apparently.
As for the push-rod V8s, the single cam solution with rockers and all is a neat and simplistic solution, which has bothered many engineers over the years because the
reciprocating movement of the rods is seen as a bad thing per definition. This is why the Wankel was born btw, from the naive concept that rotating is always better.
First of all, with modern FEA and materials, the reciprocating mass can be kept at a minimum, which often makes the valve itself the speed-limiting factor anyways,
why I'm certain that a purpose-built racing push-rod V8 of today's technology with pneumatic valves could rev almost as good as a OHC, without any limiting rules.
Secondly, the idea of rotating motion being superior to reciprocating is rather childish, just look at nature, ever seen an animal with wheels or a fish with propeller?