What I meant about Phase Shift 2 coming out only two years after Phase 0 is more about how I think it's just a callback. Readers see this line, maybe flip through Phase 0 again and go, "Oh, that's neat." Clavis had only finished talking about the world being a repeating dream of God's, and then he says that he can't remember the name of that person because he's now a part of the repeating dream. That says to me that at some point he wasn't, but now he is. With that in mind, I find it much more probable he's talking about Jin's brother than Naoto, if Naoto was even planned at that time.