Neville: I don’t know if some Lubavitch eat Cholov Stam or not. However they do hold that “DE” is considered completely “Dairy” as opposed to others who will eat “DE” after eating meat.
As for the OU, they do not use the designation DE on anything. At times, they will use the “D” designation even though the product is Pareve. You can call the OU about an individual product and they will give you the current status of that product (e.g. certain types of Oreo cookies).
I am also not sure if your last statement is accurate.