Without doubts Vitalik Buterin's death will strongly affect the price of a coin and its further development. But I don't think that the coin will die together with him forever.
If the project is correctly built, no death of Buterin will be able to bury Ethereum. The work at ETH team established, is not this ever the Ethereum Scam.
His death doesnt mean is over, if he dies, everything still continues and there will also be new ideas that are better than his. Thats how it is, things dont just end like that just because the leader died, there is always an assistant so that when the leader is absent tomorrow the assistant to the leader can always pick up from where he left off.