There could be a new coin if a part of the community continues mining on the legacy (before the fork) chain. The fork is going to invalidate blocks mined by equipment that is currently holding ~45% of the hashrate, I don't see this mining equipment just going to trash and miners using it just accepting to throw away their now main-chain-useless miners, so in my opinion, there is a very high chance the legacy chain will be maintained hence giving birth to a new coin.
Keep in mind that, unlike , for example, Bitcoin Cash, Sia coin has very special purpose, and for
that purpose team that would make new coin would also have to build software for storage network, too
Otherwise they'd mine coin that noone actually needs