The follow-up to the billion-dollar global hit that earned Joaquin Phoenix the Best Actor Oscar statue back in 2020, Warner Bros. spent yesterday promoting the mature comic book sequel “Joker: Folie à Deux” at CinemaCon 2024 in Las Vegas and unveiled a new trailer. And that trailer has raised all sorts of questions, including how much of a musical the film is and how different it will be from the original “Joker” film.