I haven't read this whole thread, I assume when we say cupping we are mostly referring to front tires...
If you are braking, engine braking, coasting, or even just maintaining speed through corners you are adding load to your front tire, which will affect how the tire wears.
If you are slightly accelerating through corners like you should (see Twist of the Wrist 2), you are taking load off your front tire. This has lots of other benefits also.