“So those relying on Rav Moshe’s heter for Cholov Stam should drink such non-hechsher milk in the U.S. just as they would drink OU-D milk in the U.S.”
Only if it is straight milk. Look at the ingredient panel, sometimes vitamins and other things are added which may require a hechsher. again, dont believe me, call your Rav, or one of the kashrus agencies.