How long until AI can measure my brain response and adjust the script in real time to make the film less predictable, more exciting, relaxing, humorous or engaging based on how I'm feeling?
It's not a massive leap from what you described.
While I think this idea has a lot of potential, it bugs me too.
And once AI is capable of replacing the "social experience" of movie viewing, humanity might not be far away from having rendered itself obsolete.
A group of friends all contributing in some way. Afterwards discussing the parts of the film that they might have been responsible for willing into existence.