Exactly what I was thinking when I saw a
recipe that included
saccharin 
What in the world?
Sweet tea is just brewed tea with sugar added (while the tea was still hot, of course), then poured over ice. Even in the south, the degree of sweetness varies with the person making it. In our household, we generally add about one cup of sugar for a large pitcher (probably 1/2 to 3/4 of a gallon). When in a southern restaurant, if you say "tea," the server will assume that you want sweetened iced tea unless that is not an option. Down here, you have to designate that you want
unsweetened tea.
But the really important question - what exactly do they serve at WDW? If it is the pre-made concentrate (Lipton real-flavored iced tea) then it is NOT real iced tea (freshly brewed)!