the way i see it theres a reasonable chance that "spirits deconfirm characters" could just be another fans assumption that sakurai will end up breakingRegardless of what Sakurai meant, let's not worry ourselves over it just yet. We have another shot at DLC, and that's something we can take a breath of relief over.
Ignoring the "game worlds" comment, I think our first line of business is Spirits. The best thing that could possibly happen to us is no new Spirits at all, but if we were to get some, what would it mean? Would that be a deconfirmation? SMM2 and FE:TH didn't get any, so there's a good chance SwSh could be passed over too. Still, it's something we need to be prepared for.