As far as I know Leech was living with the Future Foundation kids and they are currently out in space.
Fabian Cortez may already be alive again but who knows if he´s still on Krakoa or went somewhere else, he has a horrible relationship with the Acolytes after betraying them many times, with Exodus, with Magneto and the X-men, so there´s a possibility he went somewhere else or is keeping himself close to Emma since they recently worked together or Shinobi Shaw since they were partners on the Upstars group. He´s supposed to be very rich so it would not surprise me if he has a home near Krakoa but also somewhere else.
Now that we are talking Acolytes would be nice to see Amelia Vogh again she used to have a close romantic relationship with Xavier back in the day and also was Magneto´s confident and second in comand with the Acolytes. She and Joseph I would like to see around Krakoa.