Again, that was the problem with the vague comment(s) Bran has made. Can I blame him for what happened to Dany? Yes...and no. The writers failed to make it clear just what Bran knew and when.
So it comes down to two basic possibilities (with shades in between). 1. Bran gets totally random flashes of what is going to happen, such as 'he needs to go to KL to be king' or 'he needs to sit in this courtyard because this is where Arya offs the NK) or, 2. Bran spends a great deal of his time looking at the future and knows the details and acts (or doesn't act) so those details will come to pass, either because that's how things have to be, or because that's how Bran wants them to be.
I don't think it was ever made clear if Bran can do anything to change the future? Or is it through Bran's actions and/or inactions that cause the future to happen as it should?
There are a lot of possibilities but no actual canon/hard answers because Bran was written too mysteriously in the show.