I think you're colluding two separate things there.
One question is "how should the story be interpreted"? And I agree with you—like any work of art (music, painting, sculpture, etc.) this is largely up to the viewer/listener. There is no "right" or "wrong" way to appreciate art.
But that being said, it is certainly true that 3rd-party details CAN and DO alter how that art is perceived (whether "right" or "wrong").
Or to put it more succinctly: there certainly IS a change; but the nature of that change is up to the viewer.