Bran, since season 1, has always been lured to the mysterious Crypts of Winterfell. Even those that protected him (Hodor and Osha) feared to enter the Crypts of Winterfell per Bran’s request. Bran often had vivid dreams of The Three-Eyed Raven leading him to the Crypts. He even believed he had seen his father in the crypts prior to his death just as his brother Rickon did.

Bran, at the time, may not have known what mysteries lay beneath Winterfell. Perhaps the visions by the Three-Eyed Raven (Jojen) showed him some hidden truths to Old Nan’s fables and why those around him were so terrified of the crypts.

Bran Stark in season 7 dissociated himself from the Stark claim to Winterfell. He told Sansa “I can never be Lord of Winterfell. I can never be Lord of anything. I am the Three-Eyed Raven.” Bran explains to his sister that he can see everything, but that he needs to see better. So when the Long Night comes again he will be ready.

The Three-Eyed Raven is just as mysterious as the Crypts of Winterfell. Fans have yet to learn what Bran is capable of with his warging abilities or more importantly what Jojen meant that Bran will “–never walk again, but will fly.”

Bran has been left out the teaser trailer because he is the Three-Eyed Raven, not a Lord of Winterfell. Therefore, his path and role in the long night will play out differently from his siblings. That path hopefully we will see more in the full trailer!