In your personal narrow definition
sure
Don’t expect the world to conform to such narrowminded ideas, when they miss the essence of the idea of what is canon. Traditionally, books aren’t put to film before they are finished writing. That is how your train of thought came into being. “It was first, therefore it is the original.”
If we assume grrm made a rough outline for the entire series though, that was before the show got to it. So while not published, it did exist in some capacity.
Also, a thought experiment. Imagine leonardo da vinci managed to travel back in time, and tell another painter about the mona lisa. That painter then paints his version of it, would that then be the original mona lisa? No, while not in chronological order, it is an impression of the original.