Why do the New Mutants exist? Why are they a team? Cyclops runs the X-Men as one giant army, not separate squads. So, why do the New Mutants exist as a squad? The answer isn’t what you expect.
When the Savage Land Mutates hear of Asteroid M rising and the return of Magneto, the mutate Worm forces all the other mutates to come along to offer themselves to Magneto who they see as their creator. Sam's New Mutants squad is sent to deal with them. Meanwhile Emma and Scott are discussing the point of Scott allowing the New Mutants team to exist.
While Cannonball fights Sauron, Karma is fighting with Worm for control of everyone on the ship. She wins by showing that while Asteroid M has risen and Magneto is back, the island is the X-men new base and Magneto serves them now. At the same time, Emma deduces that Scott is looking in the original New Mutants squad for his eventual successor as leader of the X-men. He explains that Xavier's dream has taken a back seat in the last few years but someday they will need that dream again and the original New Mutants were raised BY Xavier in his dream as oppose to all the other new members and teams. She naturally assumes that he is refering to Cannonball the entire time, but just as Karma is finishing the battle and arranging safe passage for the mutates back to the Savage Land, Scott lets her in on the truth "I said i am looking for a replacement...I never said it had to be Sam."