Personally, I saw that moment as Magneto sucking the air out of the room from Xavier and laying the seeds to be placed at a spot as close to the top...
All he needs for a generic template is some hair, and people lose strands of hair all the time. All he needed is to get his grubby hands on one, and...
They have also gone magic adjacent with the Astral plane - the episode where the Shadow King takes over Charles' body and Jean has to give an assist...