I couldn't make much sense of the trailer, so I looked up a plot summary.
Apparently, a man scientifically proves the existence of an afterlife (how? what afterlife? is there an afterlife afterlife? so many questions...)
Well...if there is
an afterlife, I would think someone will eventually find how it works. But as for the details, of said afterlife, I haven't seen the movie.
In fact your questions, and many others, are potentially part of the discussion. I'm more interested in the world-reaction to the information, though. Which as you pointed out, they have portrayed with the potentially controversial result, being:
...revealing this to the world caused a spike in the suicide rate.
Not just a "spike," millions
of people killing themselves to try to get there.
The woman interviewing him asks if he feels responsible (imo, he's not) and soon after, a member of the filming crew commits suicide right in front of everybody. Stuff hits the fan, cue some sort of Shyamalan twist.
Everything is derivative of something. Even Shyamalan wasn't the first to use the kinds of plot twists, that he is known to employ. Hitchcock was before him.
I am more hopeful than you, just because I figure that Robert Redford has a lot of scripts to choose from, and he must have seen something in it. Acting can make or break a movie, so I'm looking to Redford to raise the bar for the rest of the cast. Plus I like Mary Steenburgen, who plays the interviewer.