Karma, aka Xi’an Coy Manh, was an original member of the New Mutants in their first comic book iteration.
We know that Game of Thrones‘ Maisie Williams and The Witch‘s Anya-Taylor Joy will be headlining the cast as mutants Wolfsbane and Magik, respectively.
Given that Karma is a major member of the New Mutants, that rumor at least certainly seems to have credibility.
The two most popular theories for who the role could be are heroes Armor and Karma.