What's interesting is the apparent disconnect between blockbuster's trailers and the footage which actually makes it into the final product. So often trailers will completely give away the majority of a film's plot, making it almost unnecessary to bother seeing the full movie. And then there are trailers for major franchises like Star Wars, which will often contain frames and scenes which are nowhere to be found during the movie's runtime.
There's apparently a reason for all of this, though, according to Rogue One: A Star Wars Story editor John Gilroy. He recently spoke to the good folks at The Independent about his editing process, and why so many Rogue One trailer moments didn't make it into the final film. When asked how trailers affect his work as an editor Gilroy said,
I ignore it. A trailer or a comic-con piece is a totally different thing to what we're really doing. But, it's really nice to clock. What the early trailers on Suicide Squad did was show Warner Bros.Read more at Cinemablend