All I can think is it's the Heroic Epic. I don't know anything about pre-patch release or instant victory, but it's the only national wonder that could be an answer to an obviously misleading clue.
It doesn't really work since the morale promotion is never obtained in any other way, nor is it an experience boost, so it's not like a victory in any sense at all. Nor does it even work metaphorically as a tale of victory.
I was going to say Palace but your pondering about "maybe G&K additions also do this" had to mean something like this, giving a modification to existing units. In fact, I suppose you'd say the National Intelligence Agency would count, since it gives experience to spies, as though they won against another spy.
