I like Coca-Cola. When I heard that Coke was launching a "new" product, my interest was piqued. What would they do?
I feel let down.
It isn't a new product. They reformulated an existing product, and repackaged it (link).
Apart from small tweaks to the formula, its appears that they added more red to the black packaging, and changed the name from "Coca-Cola Zero" to "Coca-Cola Zero Sugar". From a trade dress perspective, retaining the black and adding more red makes sense. However, from a name perspective, adding a generic descriptor or, at best, a merely descriptive descriptor to the name doesn't make sense