"does NLP really need to bring novel ideas for it to be recognized?"
Of course not. It could be synonymous with "best practices." But even if it were identical to best practices, it uses set of unique terminology which makes it harder to understand. Why does it do that?
That I do not know.
However, that is not always the case. AFAIK Hypnosis after Milton H. Erickson is also part of NLP and similar terminology (if not the same) is used there.