Vitalik cannot create a personal initiative to change the ethereum protocol. Ethereum itself has a repository of EIP lists from the community and the implementation approval involves the entire core team. Since its launch ethereum has had 2 forked coins as forms of rejection of the new protocol, ETC and ETHW. Assuming ethereum will have a lot of ecosystem chaos after changing leadership and no longer using the EIP system as consideration of improvements, I think there will be many other forkedcoins in the future.

Regarding price, I still believe that the law of supply and demand applies. In fact, what we expected went the other way, people don't care about de/centralized.