I don't think they're making everyone 'New Mutants' so much as this being fans of other young mutants getting shafted again. We'll want stories about characters like Hellion, Surge, Anole, and Mercury...and we'll get the old "They're appearing in New Mutants!" excuse where they'll just be wallpaper, brief cameos, or generally jobbed in favor of the 'New Mutants' and whoever the writer's pet characters are.