HBO hates spoilers. They really hate spoilers about Game of Thrones season 8, even though fans clamor for them, especially with that season still a year away.
Actors are extroverted and social. They like sharing their lives, and actor Wilf Scolding, aka Rhaegar Targaryen, recently did that and quickly regretted it—because letting his Instagram followers know he was in Belfast, Ireland was a big tell: He's like coming back in the show's final season.
In case you aren't totally up on show history, here's the issue with Scolding's photo: Thrones is filmed in Ireland, and his character is dead.
Why would the actor who plays Rhaegar be there unless there's some kind of serious plot point involving Daenerys's nephew, Jon Snow—like the fact he is a strong contender to sit on the Iron Throne.
After all, Rhaegar bought it at the hands of Robert Baratheon during the Battle of the Trident, and that took down the Targaryen dynasty. Scolding would only be back in season 8 to film flashbacks.
At minimum, it seems obvious showrunners are working to tie plot threads together. That, or Wilf Scolding took the photo down because he was just taking a trip to Ireland and didn't want crazy fans to know where he was staying.