That is not why bitcoin comes to be decentralized, it's because it's the p2p. Although there is a creator satoshi, he already disappears and he didn't touch his coins too. Don't think about CSW. Why it's decentralized is that no one controls it because it's the network. Its not private but Public.
Even without Satoshi Nakamoto, Bitcoin is decentralized. He opened a genesis block and published the news two months before the block opened.