Now I want to watch this! The comics that I assume this was based on, by Chris Claremont and Bill Sienkiewicz, are also pretty rad. And there's a cool academic book called The New Mutants: Superheroes and the Radical Imagination of American Comics that deals partially with these comics (along with many others) through the lens of queer theory that I bet you'd enjoy.
As for ranting about Dark Phoenix: Do it! I never saw the movie, but the score is really good...? I had it on loop when I was reading the original Dark Phoenix comics earlier in quar, lol.