I think the idea of revolving the whole plot around the Dyad makes way too much sense. Suddenly Palpatine has a clear plan that doesn’t involve Rey killing him and his spirit passing into her, Kylo has something to reveal to Rey in the hangar that isn’t her being a Palpatine, and presenting the Dyad as inherently part of the Dark Side (even if that turns out to be untrue) sets up a decent dilemma on whether or not Rey should kill Palpy to take his throne if it means turning to the Dark Side.
True, but with what footage we have available we’d still have to use Rey getting close to killing Palpatine for his essence transfer. Maybe in the hologram scene Palpatine could say that he’s sensed Kylo Ren’s death, which would explain why he’s suddenly okay with the essence transfer plan instead of hoping Ben follows Rey to Exegol. And then when Ben suddenly shows up he’s like: “Oh, I thought you were supposed to be dead. Too bad your coming together is gonna be your undoing.”