Cupping from a bad shock would occur over a greater section of the tire tread. The Inner shoulder wear the thread starter is seeing is primary caused by VWs stock alignment settings (toe in combined with high camber, constantly scrubs the inner shoulder rolling down the road). VW sets up the alignment on these cars to error on the side of being super stable at highway speeds for the lowest common denominator of driver. I've seen it many times after owning a 2 X mk5 gti s, a mk6 gti, currently a mk7r and an alltrack (to a lesser degree on the alltrack due to the less camber the alltrack runs in the rear). What you are seeing on the inner thread block I believe is actually called feathering.