Is this the case with the oldest *British* universities? I had the impression it only applied to the oldest *English* universities.
Unless of course, as frequently happens, they study subjects which they did not study at school. In the case where topics *are* repeated, it is commonplace for the Scottish university to allow the student to start in the second year of that subject. Where this is a well known standard situation, the offer is sometimes made as part of the original acceptance. Whether or not that is the case, it is usually possible to enter into individual negotations. For example, this doesn't just apply to things studied at school, sometimes a student has acquired special expertise outside school.