Greetings in that Divine and Most Precious Name of Our Lord and Savior Jesus Christ!
No. He specifically insists that Chalcedon explicitly approves of one nature and explicitly holds it as being as equally Orthodox as two natures. He's not talking about Chalcedon as interpreted by Con.II a century later. He says it's explicitly in the decrees of Chalcedon itself.
I've read some explanations from the EO perspective which explain that original intent
of the term dyophysis essentially connotates the same meaning as miaphysis in the context of being a composition. Perhaps this is the same vein of thinking he was coming from? I am of course extremely interested to know if the language of the Council of Chalcedon explicitly accepts or rejects the term miaphysis, because I do know the term dyophysis is used for "two natures" in that Council, but I am not sure as to if there are references to "one" in the context of "mia" or "mono." Again, the Oriental fathers object to the term dyo as being two, and argue conceptually that this term implies a separation, however in ecumenical dialogue over the past hundred years the EO have openly accepted the term miaphysis to describe their doctrine of dyophysis, which to me, seems to say that they are willing to interpret the term dyophysis in the same context which Oriental fathers interpret miaphysis (ie, a unity of two as one without separation, distinction, mixture, or confusion)
Really sometimes it seems like a case of