even from knowing who Satoshi is, a man or a group of people, - what would happen to BTC itself in the long run?
Nothing would happen. I read a Peter Todd quote a few weeks ago after the fake documentary named him. I can't find it now, something along the lines of, "spent many years reading the source code to understand Bitcoin. Bitcoin is that published code, it is not the original developer's person"
That's a terrible paraphrase. If someone can link me Todd's original, I'd be grateful