Two issues surrounding this preventative maintenance action:-
1) this action is being described in a generic way, on these 1.2TSI engines and some others of a similar design, the water pump is located at the other end of the engine and so is not involved with the cam belt at all - that inclusion when replacing a cam belt was probably correct for every other cam belt change as very little extra labour is involved if it is replaced while the cam belt is being replaced and it was one of the wear and tear items in the cam belt drive train ie carrying the load of the cam belt drive, the water pump failure would lead to serious engine damage as it would cause a failure of the cam belt.
2) it seems according to VW Group, that this newer and much more expensive design of cam belt should last for a lot longer than the previous generations of cam belts, and, I'd hope all its supporting items in the cam belt drive train. The official service notes to workshops on this cam belt is "examine along its entire length at the (maybe) 6 years point and replace is showing any damage/break-up - repeat this examination every year after this". VW, Audi, SEAT and Skoda UK importers, who are normally VW Group AG owned, allow their franchised dealerships to leave that cam belt issue as it was for previous generations of cam belts, and possibly the only reason for that is that it allows these franchises to generate more work.
Now that is how things are, what you decide to do with your money and car is up to each individual, I have always in the past replaced the cam belt on 1.4 16V BBY and BXW engines at the 4 year point on earlier engines and the 5 year point on later engines as recommended by VW Group, but on these "belt for life" or "long service belt" engines, I'm taking a slightly different approach and plan on getting the cam belt replaced at the 7 > 8 year point in this car's life which will equate to roughly 50 miles.
