The study suggests something that is true in general for people, it doesn't apply to every person in every case. Like I said, in most cases I'm not bothered by spoilers. However, in this particular case, I felt a diminished sense of enjoyment of that movie. I base this off of my experiences of other twists of similar or lesser magnitudes and how much enjoyment I got out of those. I liked the movie, I liked the characters, but I was missing the punch at the end and I knew it. It felt like a letdown. Hell, I would've probably liked the movie more if it hadn't had the twist because knowing the twist and knowing I wouldn't be surprised made the movie end rather flat.