If I target the Mystics ability with No More Mutants, does Scarlet Witch have to roll? I'm asking because the next sentence says "any other" which seems like it excludes Scarlet Witch.

Since it says any other I'd say she keeps her mystics

She doesn't have to roll for unless both teams have the same Scarlet Witch on there team. Then she does have to roll when the opposing SW uses it.