1) Warn readers there are "spoilers ahead" and then proceed to actually say something.
2) Withhold from writing a totally vacuous post and write about something else instead.
As it is this reads like an Onion article titled "Man, that twist at the end of Empire Strikes Back was totally crazy!"
People are just trying to thread the needle of how to handle discussing this movie in this short window so soon after release. We want others to watch the movie so we can both have more people to talk about it with and so we can eventually talk about it more openly. But as is, the movie just came out a few days ago so people are trying to not diminish anyone's experience of watching this movie for the first time without knowing what transpires. I realize this likely all sounds frustrating to someone with little interest in the movie, but it's all a good intentioned way of engaging with a very special piece of art.
I'm glad that pieces like this exist, encouraging people to go and see it, and I look forward to reading more of (1) once I've seen it.