Turns out when Boone said they were making "a full-fledged horror movie within the X-Men universe", what he meant was they were making "a full-fledged horror movie within the X-Men universe". Without the word "mutants", The New Mutants actually looks like a horror asylum movie that has nothing to do with the X-Men. The trailer suggests that director Josh Boone and his cast of young superpowered people have made a film quite unlike any X-Men property we've seen before. "We love that Fox wants to make all these different X-Men spinoffs as drastically different as they can". New Mutants follows young mutants that recently received powers, only to be held against their will in a secret facility, according to the premise from IMDB. We haven't seen it as a superhero movie whose genre is more like "The Shining".
After the filming was finished Stacey Snider (Fox chairman and CEO) described the film as "a haunted-house movie with a bunch of hormonal teenagers". Providing jaw-dropping art to a number of New Mutants comics, it's good hearing a classic creator be proud of the upcoming movie.
It has a planned release date of 13 April 2018 (12 April in Australia) from 20th Century Fox.