Bunch of horse hockey. They changed the twist from 1:14 to 1:12 to accommodate ball powder, vs. the IMR powders used with the original 1:14. And do you know why it was originally 1:14? Because that's what the AR-10 was, the gun the AR-15 (and subsequently, the various prototype M16 models) was based on. They changed the twist rate to 1:12 with ball powder because it stabilized the 55 gr. FMJ better. Fast rates of twist were not a thing back then, except with varminters, and even amongst them, 1:10 was considered enough..It was NOT designed to create 'massive wounds', even though they occasionally happened. The terminal ballistics with M193 ammo are mostly connected to what it hits.
I had a Drill Sgt. spout that "maximum wounding" crap in Basic, and even though I paid in pushups for it, I corrected him right then and there.