Game of Thrones showrunners claim that season six won't spoil the books
At one point there was hope that George R.R. Martin would complete "The Winds of Winter" before the HBO series returned to television, but sadly that was not to be, which puts the television show in an interesting position as it may possibly be revealing details about Westeros before George R.R. Martin's books will have the chance to. However, while Game of Thrones showrunners Dan Weiss and David Benioff know the broad strokes of how Martin's tale will conclude, the television series will be different enough that it won't be spoiling the events to come in the books.
People are talking about whether the books are going to be spoiled – and it’s really not true. So much of what we’re doing diverges from the books at this point. And while there are certain key elements that will be the same, we’re not going to talk so much about that – and I don’t think George is either. People are going to be very surprised when they read the books after the show. They’re quite divergent in so many respects for the remainder of the show.
Game of Thrones returns to HBO on April 24, 2016.