What this means for fans is that what you see in the ending of the series might actually differ from the book. This was revealed by Martin in an interview with Entertainment Weekly where he said, “I haven’t read the [final-season] scripts and haven’t been able to visit the set because I’ve been working on Winds. I know some of the things. But there’s a lot of minor-character [arcs] they’ll be coming up with on their own. And, of course, they passed me several years ago. There may be important discrepancies.”
The showrunners have confirmed this as well, where they state that there will be parts of the series which differs from the books, but they will not be telling viewers what those differences are so that they can find out for themselves if they’re interested in reading the books as well. Martin also spoke about his feelings on the show coming to an end.
“It’s been an incredible ride. And almost all of it has been great. Obviously, I wished I finished these books sooner so the show hadn’t gotten ahead of me. I never anticipated that.”