I doubt he would know that. Im not sure exactly how all this greensight stuff works. But it has something to do with Weirwood trees, blood, children of the forest, etc. I doubt he'd know about what happened in the Vale.
Also, telling the Vale about Lysa's death wouldnt help anyone as Sana covered it up.
Also, telling the Vale about Lysa's death wouldnt help anyone as Sana covered it up.
Bran should be heavily invested in the White Walker fight, and not kings landing and the Game of thrones. A lot of stuff that people are frustrated that he isn't saying would be extremely trivial and would only cause more rifts and problems. Telling anyone that Jon is a secret Tararyen is just a waste of time.
On Olenna - She overvalued her control over the reach. her son was the last lord of Highgarden and with no heirs the realm was ripe for the taking. After meeting with Dany she went back to the Reach only to find that the Lannisters and Randyll Tarly had got the rest of the lords on side first.

