User blog comment:Khalael/Canon Policy Discussion 1: Space Marines/@comment-4608429-20131105174533/@comment-3258762-20131105205056

I believe, though I may fully be wrong, that Truly assumes that Loyalist Traitors means Renegade chapters who still claim to be loyal to the Imperium. Those are fine, according to me. What they think and what is doesn't have to coincide with each other.

But, as Cal stated, we cannot have loyalist chapters that draws Gene-Seed from the Traitor Primarchs. In fact, I doubt the AdMech still has that Gene-Seed.