If you order an iced tea in Canada you are getting Nestea/Brisk like 95% of the time. Both are sweet teas, but are marketed and labelled as "Iced Tea", not "Sweet Tea" - ask our American beverage overlords Coke/Pepsi why

If you are in a cafe, or some other place where the expectation is that they brew their own, then yes, it's generally unsweetened - but it's also usually explicitly labelled as such on the menu so you know whether you are getting brewed tea vs a glass of corn syrup