The world of bitcoin seems to be a world built with puzzles... privacy to protect identity and even now many of us do not know who the real Satoshi Nakamoto is... he is said to be the inventor of Bitcoin, and I am sure the public reaction to his emergence will be something sensational...
I thought that no one knew who Satoshi was, the way you wrote it, it seems that some people do know but don't want to say? In my opinion, there is no sensation here, neither about who he is, nor when he would appear - because he or they have done their job and there is really no need for them to ever be present in public again.
What do you think when Satoshi Nakamoto succeeds in proving that he is the real one and then appears publicly?
Will the cryptocurrency market collapse or will it actually improve? I like the wild logic that might be in your mind.
Satoshi can prove his identity only if he signs messages from one of the first BTC addresses, but even if someone does that, it would not mean that he is the real Satoshi - because anyone can get hold of those private keys at any time. However, I think that these private keys were probably destroyed on purpose so that this would never happen, which means that the mystery will continue to remain a mystery.
I don't think we can know how the market would react to such news, because part of it would be delighted by it, part of it would surely be afraid that Satoshi would dump all his BTC. Therefore, it is better that such a thing never happens.