GRRM's writing style hasn't changed in fifty years. It part of what makes him popular. He constructs a story, knows the major plot points, and how it ends in order to fulfill his vision of the message he wants to send. He is very message driven.
He also does not care about the characters or subplots along the way. It doesn't matter to him if a character dies or does any wild thing, as long as it's true to the character. It's a brilliant way to write.
It also makes it very clear that the end of the television series is not the end of the books. Because the tv series has no message or definitive ending tied to the major through line. It's contrary to GRRM's writing style. I'm pretty sure he's laughing his ass off at the way it ended on the screen.
If any character did something without a rational reason, then D&D simply did not understand the characters motivations enough to write it properly. Bran was not 'normal dude in wheelchair' at that point in the story, but that's what we got.
Sadly, you can go through the character list and see that the only thing that D&D got right was the necessary plot points, which were spoon fed to them. So many characters became one-dimensional.
I am very much interested in the story of what happened after Bran was crowned an season eight ended, because that is so clearly inconsequential.