Ah, but that comes from an EU novel. In canon, it hasn’t been stated what the catalyst was for Anakin’s birth, only that he was created by the Force to be the chosen one.

Like I said, perhaps its best to leave this up to the audience’s interpretation. They can imagine that the Force made both Anakin and Rey at just the right times to coincide with their needed role, or they can imagine that Palpatine created them at the most opportune time for himself. Or a combination of both.

EDIT: The biggest problem with this idea in general is where it would be located. It reveals that Palpatine had a role in Rey’s conception too early where it’s currently at - that needs to be saved for the hangar as it’s the crux of all this. And it can’t be mentioned in the hangar because we need to use the same wording from ROTS to keep within the bounds of familiar Star Wars to sell the reveal as authentic.