If you read the thread then you would see many examples where given. BUt the only proof that you are willing to accept is that the devs or phil spencers comes out and says "yes its true, MS is paying us to keep parity" wich will never happen and you can live in denial saying your right.
you really think there wouldn't be a disgruntled developer somewhere that would come out and say what microsoft's policy is here? Trust me, if Microsoft was forcing graphical parity, you would have heard about it. That isn't a policy that would sit well with a lot of people, and would quickly become public information. Whether through insider leaks, disgruntled developers, or annonymous tipsters, that iformation would have come out.
All the examples people have given are just conspiracy theories derived from online forum dwellers. Nothing has been confirmed or even talked about by actual gaming press because there isn't anything to talk about. It is just conspiracy theories...