President of Animal Kingdom
Test groups and surveys. They let a representative sample of the general public and film critics get a sneak preview.That's what I'm thinking. How does Disney know that film is going to be a hit?
Disney knew GotG vol 2 was going to be another hit and doubled down on it with Mission Breakout and greenlighting a Vol 3 before 2 was out.
If the test screenings go poorly they can delay the release and reshoot (although, reshoots and after productions changes are normal even for a good movie, they're also attempts to save bad ones). And if it can't be saved... straight to video.