Stratford International (used so much for international services) is in a magical alternative dimension where it sits way outside the boundary of zone 6, or even zone 9.
If every ticket sold for the Olympics includes a Travelcard, will that be valid on HS1 or will SET be standing there selling HS1 supplements to everyone that assumes their Travelcard covers everything in the zonal system (Heathrow excepted)?
I am guessing the latter, so nice easy money and what SET has presumably been waiting for, especially if GA falls to bits during the Olympics and it becomes one of the only ways to get to Stratford (let's face it, the Central Line will be rammed beyond belief).