I think a better comparison is marketing orange juice as sugar free (because no sugar was added)
"Sugar Free" is based entirely on the amount of sugar per serving size of finished product. It does not care where the sugar came from. Any product that contains less than 0.5 grams of sugar per serving can be labeled "Sugar Free".
This has the fun outcome that tiny candies made entirely of sugar can be sold as "Sugar Free"
Indeed, that was the point of the meraphor. By the same token it is wrong to say origi nal coca-cola was cocaine free.