Well I'm not sure I'd believe (the tech) that they gave up on the ECM/EDM process. They're given us bad info before.
I agree though that some guns with ECM/EDM rifling look softer than others. While my new 66-8 & 69 snubbies (mfd. Apr-2017) both have good looking rifling they are not quit as sharp looking as the broached rifling of my PC 625 & PC 627.
I think I'll hold out for more confirmation.
.
66 Combat Magnum - muzzle recrowned
(-02b)
.
69 Combat Magnum - (muzzle, crown)
(-012a)
.
625-8 PC, barrel crown, after
(-01a)
.
627-5 PC, barrel crown, after
(-01a)
.