It now appears that the New Mutants script has since been re-written (or is being re-written) by two of Boone’s trusted collaborators.
Among the numerous X-Men films, sequels and spinoffs that are currently in some stage of active development is New Mutants.
The New Mutants movie adaptation is being co-written and directed by Josh Boone, a filmmaker who made his name with a very different sort of young adult adaptation: 2014’s The Fault in Our Stars, based on the John Green novel of the same name.
The duo are presumably revising the earlier New Mutants script draft by Boone and Lee (with Boone’s oversight), so that the end result is that all four screenwriters share writing credit on the film (either for screen story and/or screenplay).