I will just say "if you say so...", but it's just neither my view on the thing, neither the one of any teacher I had over the years, including music college teachers, which some were among the greatest musical minds I've ever met.
I agree to some extent with what you said but, trust me, I know my chords
Maybe you should just think about/review theory on guide tones a bit more, it's all there really, and it's what makes this note that you played with your pinky a 9th.