That's not how it's done. It's even more cynical.

There's a handful of really good trailer/ad editors in LA and they do most of the trailers, for many studios. They each have their speciality, eg:making a not-really-funny movie appear an hilarious comedy.

The marketing people at studios are looking for specific kind of movies for specific demographics and times of the years. If they haven't got what they want -which is most of the time - they shamelessly fake it with trailers. The trailers editors are experts at creating out of any movie what the marketing people have decided will make the people go to the theaters that month/years.

If they used these methods that owes more to propaganda than advertising to sell products they'd get sued, but for trailers it's like they'd still stuck in the 40s when advertising could say anything about anything without any legal consequence for lying to peddle their goods.