Lilmod, they just wouldn’t eat from the dairy part of people’s homes. From what I’ve observed, I think Lubavitchers actually WILL eat chalav stam DE. But, I’ve heard an interpretation that, even if you do eat chalav stam DE, you shouldn’t do so with OU hechshered things because you can never truly know that it’s just DE as they don’t differentiate.
After that YWN article about how the Rav Moshe heter no longer applies and how the OU admits that we’re back to choosing between the Chasam Sofer and the Pri Chadash, I’m hard pressed to understand why more people don’t avoid chalav stam DE. If you hold it as a halachah, not just chumrah, that equipment is treif for you.