American Horror Story: Who's Still Alive on Roanoke, and Who Will Survive?

There are a few people who were involved in My Roanoke Nightmare who haven't surfaced since the big twist in "Chapter 6." We still haven't met the actress who plays Scáthach in the reenactment (Lady Gaga), nor have we met the actor who portrays Elias (Denis O'Hare). Could Sidney have made plans to involve them in the production later? Or will we simply never see them again? At this point, it's unclear.