Once upon a time the Harry Potter books were still coming out and while it was well known that they would be bestsellers and book shops would have lines out the door to get it on opening day, some people managed to get ahold of some basic spoilers for the book, drove to the stores and shouted them at the people outside like an annoying hit and run. They filmed themselves and drove off giggling, but what about the “victims” of this petty crime?
I think chances are good they still got and read the book so the spoiler wasn’t a barrier for that, but how much did knowing the ending really ruin the story for them? I’m aware of the study from UCSD on this topic, but I want to reach a different conclusion than saying, spoiled stories are more enjoyable because now you can focus on the little details in the narrative.
Certain directors and writers even put spoilers into their own stories. For example, starting your movie with a scene from the middle, or right before the climax, or a “you’re probably wondering how I ended up in this situation” is normal, even if it doesn’t happen in every movie. Parts of the story are spoiled intentionally for the narrative to flow. No one would be mad if they spent a ton of energy avoiding a spoiler for the next Game of Thrones episode, only for the opening to technically spoil the ending of the episode. Even in the business they’re fine spoiling moments for their audience.
The thing about spoilers is that you know some piece of information completely divorced from the context of the story. Telling someone before they see The Empire Strikes Back that Darth Vader is Luke’s father doesn’t explain what it really means to either character, how the movies builds to that moments and shows why it’s important, or how it influences the story and the arcs of the characters.
Caring more about spoilers and investing more emotion into a piece of media before it’s released will probably lead to more people excited and want to see it and have more reverence for it if the wait and silence is worth it, but I don’t see how it negatively influences old stories, so I don’t really see how it’s different for new ones. Stories that were written hundreds of years ago aren’t any worse because we know how they end.