One unexpected reunion in the Game of Thrones Season 7 finale was between Bran Stark and Samwell Tarly, who finally compared notes as the two most knowledgeable historians around. Bran still seemed to think that Jon was the bastard son of Lyanna Stark and Rhaegar Targaryen, but Sam revealed that Rhaegar's marriage had been annulled at the last minute, making Jon the heir to House Targaryen. Jon's erstwhile little brother warged to do some fact-checking and confirmed it, so will Bran and Sam tell Jon he's a Targaryen on Game of Thrones? Bran seemed determined to reveal the truth.
He tried telling Sam he was the Three-eyed Raven now, but apparently Sam hadn't gotten that far in his studies yet — he didn't know what that meant, much like Sansa. For what it's worth, Bran defined it only as being able to see the past and everything that's happening at present. That could put speculation to rest for a little while as to whether or not warging also gives him the ability to see the into the future. And Bran didn't even know that Rhaegar had legally married Lyanna Stark before Jon Snow was born, so evidently, he still has some backlogged Three-eyed Raven DVR to get through anyway.
Sam ditched the Citadel and returned to Winterfell to help Jon in the War to Come, and his first deed was to help Bran piece together the truth of Jon's parentage. Bran revealed that Lyanna and Rhaegar were his real parents and Sam told him about the annulment he'd read about while transcribing. We see a glimpse of Lyanna and Rhaegar's clandestine wedding ceremony as Bran wargs to check Sam's intel.
"Robert's Rebellion is built on a lie. Rhaegar didn't kidnap my aunt or rape her. He loved her," Bran realizes as the scene cuts to Jon knocking on Dany's chamber door. "And she loved him." We also see a replay of the Tower of Joy scene which Bran revisits, except this time, we can hear Lyanna say Jon Snow's real name. "His name is Aegon Targaryen," she whispers to her brother as she hands him the baby. "You have to protect him. Promise me, Ned."
Bran finally puts all the pieces together and understands the urgency with which he must reveal to Jon his true identity. "He's never been a bastard," Bran understands. "He's the heir to the Iron Throne. He needs to know. We need to tell him." The only question remains is: when exactly will that day come?