The New Game of Thrones Trailer Has Sparked So Many Wild Theories

Bran has finally upgraded his sled to a wheelchair. We're sure Meera is quite relieved. What's interesting here is the person he's with. It's clear he's still honing his greensight here. Is there a possibility that this person is the previous Three-Eyed Raven? It's true, the Night King has killed him, but we know Bran's powers work in mysterious ways. Could this be a flashback? Could Bran somehow commune with the Three-Eyed Raven in his altered state? We'll have to wait and see.