We’re obviously not saying that every movie needs to be a clandestine follow-up to 17-year-old movies, but it certainly should be a clear example that there’s many ways to approach and sell sequels in an age when they’re being delivered to theaters practically every weekend.
As M. Night Shyamalan has freely admitted, Split wasn’t the easiest sell as a secret Unbreakable sequel, as it’s clearly a powerful marketing angle that is just left on the table — but Universal Pictures was willing to run with the idea, and it’s clearly paid off in a big way.