I don't think it would have a need to be done because it's completely easy to make a zero calorie drink that tastes as sweet as desired and tastes very good.
The reason, as I understand it, for the drinks with for example 2.4 calories is that, ironically, after Coca-Cola and Pepsi cheapened and worsened the taste of their products by switching to high fructose corn syrup as their sweetener, with time some came to take the taste of corn syrup as being what a sweetened drink should taste like.
That aspect of taste, compared to cane sugar taste, is not from the sugar, but from impurities from the corn.
It was found how to concentrate that off-taste, so that only a tiny amount of corn derived sugar is needed to give the full corn-syrup taste, when combined with artificial sweeteners.
So no, no need. The obese can get the corn syrup taste they desire from only a very small number of calories thanks to the new technology.