What they are saying is if you want to have 6" or 7" wheels then you need to buy better brakes or we won't sell those big wheels to you. Bigger wheels and tires haul more weight and they want the brakes upgraded.
What you say also makes sense, but how would you go about ordering the 6" wheel? Also if you ordered any of the four following 1971
B - body tires (G78 x 14, H78 x 14, F70 x 14, or G70 x 14) which comes with 6" rims, it does not tell you anywhere that I could find, that you are required to purchase H.D. brakes (aka 11"), or disc brakes.
