The 2.0, or 2.Slo, has been around VW a long time. Service duty requires only normal SJ oils, as per service manuals. The VW spec is for extended drains, which VW and other played with for the last 10 years. Extended drains have not fared well for many owners, and the dealer gave good advice.
To claim going by the manual is the only way to service vehicles neglects the fact there have been numerous oversights on the matter. Sludged engines are a regular occurance on BMW, TOYOTA, Audi, VW, Mercedes, Saabs and others. Quite often it is the result of "standard service" from the owner's manual.
Despite obsessive adherence to the manual by owners with the best of intentions, it is far from the final word on the matter. The document is contrived by marketing, customer relations, accounting and various executives whom know very little about the service cycles of the engine and oil. The actual engine developers have limited input.
The 2.0 itself can run on ANY otc oil, be there no doubt. Many un-speced oils far exceed the abilities of VW 502, a old spec from 1998. I would like to see ONE example of oil-related failure in a VW 2.0, I know of none, to the contrary.