MILD SPOILERS (nothing really too detailed though)
Bleh, I started to respond but started writing a novel on my thoughts that would bore everyone. I will summarize and possibly elaborate more later.
In short, I think the series was started with the best of intentions for everyone, but its takeoff success really changed the scope of the project for everyone. I think there were possible talks of book releases and spinoffs that drastically altered the course of this show years ago based on its success. I agree with what Rob said, that once the show surpassed source material it went from a great book adaptation to simply being a "television series." I think the show springboarded D&D a lot sooner and higher than they expected, and they have been ready to put this show behind them for awhile now. (D&D is how the cool kids refer to the show creators. I want to be a cool kid.)
As far as things coming out that I am interested in, I found this to be quite interesting watch. Does it hold water? Is it the ramblings of a jaded actor? I don't know. But I will be curious to see what press about the books starts coming out, as well as press on the future HBO projects. I honestly don't know if I totally subscribe to this, but...
https://www.youtube.com/watch?v=Feft...outu.be&t=1901
Plus the prequel series we are starting to hear about. I am really interested in what talks/negotiations have happened around it. I would not be surprised if HBO or Martin made D&D basically write off the WhiteWalkers and Brann with no deeper origin story resolution, so they could use that as a basis to continue their cash cow. Several articles have stated that this prequel series will delve more into their origin. And if that is not the case, well then the S08E3 resolution of them was just pure hot garbage writing, imo. (granted, we have 1 episode left, so maybe I will totally eat those words, but doubtful).
Not to mention Martin's involvement in the prequel series. He is supposedly very involved. For the past several years he has been distancing himself from GOT show involvement under the guise of "needing more focus on his books." If that was truly the case, you sure as shit don't take on major responsibilities on a major spinoff series and eat up more of your time. I think the statement in the above vid is either factual, or we are never getting the next two books. Simple as that.
Like said, we'll see. I am more entertained in the shit-show at this point than the show itself, and like said, I am really interested to see what all becomes of it after the fact.
Well, I ended up writing a novel anyways.