I think no matter how you slice it, Moe had
to die. I don't think that Kellhus is lying when he thinks to himself that the Thought has outgrown "the soul of it's incubation" (i.e. Moe) and so I do think that the Thought would have needed him gone in that moment or a subsequent one, regardless of anything else. I think that even with all the victories that Moe had over the world, to gain control of the Cishaurim, to engineer the Holy War, to draw Kellhus to him, and so on, he was
wrong on several things.
One, he thought the world was "closed" and that the Outside was not a major influence on the Inside. We know this is plainly false. Two, he imagined that he possessed the Thought, when it was the opposite, most probably. The Thought used him, not the other way around. Three, failing to recognize both those factors, he totally misses what Kellhus will be when he arrives. Moe imagines himself the engine, where he is really just yet another cog.
For these reasons, Moe is an anachronism in the "New World" of Kellhus. Indeed, so are the Dunyain themselves. They all die, necessarily. They were tools in a bigger plan, discarded once they were of no use.
“The days are new Chigra … And far shorter than the old.”