Qui-Gon can’t appear as a Force Ghost because his training was left incomplete. However maybe they’ll create a scenario like the cave on Dagobah or Mortis where the Force works in mysterious ways for him to appear in physical form. I suppose there’s always flashbacks too. It would definitely be great to see him again.
Very excited to see Bonnie Piesse and Joel Edgerton return as Aunt Beru and Uncle Lars too!