I think this new rule is confusing. It requires that you establish a grounding electrode system at the SDS that is located outside, but it does not permit a second connection between the grounded conductor and the earth at the structure served. When I first saw this change I though it would make it just like a utility owned transformer where the grounded conductor is connected to earth both at the transformer and at the structure, I don't any wording that says you can do this with the SDS. This just requires the grounding electrode to be at the outside SDS.
The code only applies to T&M work....it does not apply to contract work.