No, there was never a Zangetsu, it was always Aizen's weaponized soul, White. Juha Bach has been manipulating Ichigo all this time, he never knew the name of his zanpakto, he forced his bankai out by will alone. He's been just as disharmonized with his sword as Zaraki Kenpachi is all this time.
Its not that his hollow was Zangetsu, its that Zangetsu was always a fraud, and White was always the source of his power.