What?
Everyone knows Bitcoin was created by single person e.g. Satoshi, so it doesn't matter if he comes out now or in the future, Bitcoin will always remain decentralized. It's possible to change Bitcoin protocols, mechanism and switching POW to POS, but that's mean he need to change everything on Bitcoin. There are so many contributors and developers helping the Bitcoin development, not only Satoshi. Even Satoshi ask them to change it, I doubt all the contributors will agree with him.