And to think that McIntosh, by his own admission, was once an active trapshooter. 'All but' is quite a disclaimer. Must mean that choke is obsolete unless you need choke for something - like for breaking a target or killing a bird beyond about 25 yards.
It was indeed the advent of the modern plastic shotcup that made 100 straight a statistical certainty (Winchester, et al), but this is only so with a barrel that will deliver a 70% or better pattern at the target plane. This takes choke at any distance over 25 yards, assuming lead shot. Steel and the harder non-tox stuff does indeed shoot very tight with little or no choke.
Mac is a good writer, and I enjoy his stuff... but physics is still physics. We may well need less choke these days to duplicate the performance of pre-plastic times, but for most long range gunning choke is hardly obsolete.
