Perhaps they should have done what Toyota did and evaluate rear and front drive through the hybrid powertrain. As you say, they started testing the E-Tron in July 2011, which is around the time the 2012 regulations were made. Actually the link you provided shows the regulations dated from June 2011. Knowing the dates helps since they had the knowledge when they started testing that front driven hybrid power would be above 120kmh. So, I think what I stated still remains a fact,
That's the direction they chose knowing it's 120kmh+ 