I've made ice cream and sorbet extensively, and wouldn't assume that the sorbet was made with wine. Alcohol lowers the freezing point. In order to lower the alcohol content to minimize the risk of ice crystals, you'd heat the wine until the alcohol is burned off. Instead of boiling perfectly good wine, I would have assumed that the sorbet was made with muscat grape juice, and was being called "Moscato" to make it more familiar to the general public.
So, I'm with Pete. They should have labelled it as being made from wine, even if they had boiled every last molecule of alcohol away.