Offhand, this sounds like its validity is intended toward propeller aircraft. Turning toward the good engine means the prop is accelerating airflow over that wing. Meanwhile the "outer" wing enjoys more airflow due to its being at the outside of the turn.
Thus the Vmca issue is alleviated by the turn into the good engine, and that meshes with the old "dead engine" rule.
Jets - without powerplant exhaust over the wing airfoil - will behave differently; Only the thrust asymmetry drives Vmca.