Just had a call with VW to book in my 2017 T6 that has 54000 on the clock for a cambelt and was told it has been changed around 4 weeks ago to a mileage based figure of 140000. I asked if the belt was to snap before this mileage what back up would VW give me with the engine being no doubt being buggered, she couldn't answer so put me though to the workshop to speak to the service manager. The service manager had no idea the frequency had changed to a mileage only based figure and told me it was four years. I got put back though to the bookings department and I got a different person who also confirmed the change to 140000 miles, he also confirmed it with his manager, he couldn't help me with what backup VW would give if the worst happened but has given me the VW Customer Care number to go and ask them. So who knows, I am a mechanic and I'm fully aware of the implications of it breaking but I also don't want to spend £700 if I don't have to!
I'll update once i speak to Customer Care.
Cheers Lee