The "CIA" is not a monolith. It's got factions - or imaginary ones created by others.
In whose interests at every stage was is to keep Saddam in power? France, Russia, Saudi, etc. Or its just politics.
Consider the Prague Atta story. Maybe its founded on a misidentification. But why were there so many efforts to debunk it with false information?
Or maybe it's just politics or resentments.
BTW, a lot to Hersh's information came from Wilson.
I agree with this assessment. Even though the story really has ex-CIA agents (not current agents) pitted against current government officials, the general impression conveyed to the public by this kind of story is one of CIA underhandedness. It makes the CIA look bad, and that's the way it will be categorized in people's minds.
So I doubt that it's CIA disinformation. It may still be disinformation, of course -- or just plain wrong. [Maybe the French are touting it!]