VW say its "for life" oil so never needs changing. I am not convinced that oil can last forever. The oil in mine would have been 20 years old now and that cant be good.
Also consider, do you know for sure that a) its filled up properly b) that someone else in the past has changed it and did they put the correct stuff in c) is spending a tenner (or whatever it costs) worth the peace of mind for the many years of ownership you will have with it. d) if the gearbox goes one day and you had not chaged it, would you blaim yourself for not checking the oil?