Nom, a person believing in a god with a body, or believing in baal, is avodah zara regardless of if the person serves the deity.
But here, they DO serve the deity. You’ll see lubavitchers say that they do mitzvos to please the rebbe. At a shluchim conference, an oved avodah zara prayed that the gathering be pleasing to the rebbe, and may he bless our efforts… Effectively a vehi noam. Shlomo cunin, chabad head of the West Coast, said after the Mumbai tragedy that the world will see that it’s the rebbe who runs the world.
It’s there, and it runs deep. It went from personality cult to full on idolatry.