Isn't he responding to the specific inquiry of the letter he received? And I don't see proof of anything here, if such a grave outing had taken place why days later would senior intelligence officials further endanger her by offering that Plame worked on weapons of mass destruction issues? (As written in the linked Newsday article.) Of course the same article says that Wilson claims that the Bush administration was trying to intimidate him and others by using her maiden name. (He, in his on-line biography, lists her maiden name.)
People were reacting to Wilson's op-ed piece where he seemed to assert that his visit was the complete and final history of Saddam and uranium. I'm still betting that Plame's name came up first as part of a sour grape explanation of why Wilson got an assignment that he was neither fit to fill or made expert on by his single visit.