Not to mention Palpatine tricking Rey and Kylo into having them both come before him would just be a total rethread of TLJ. That might’ve also been a reason it was changed, though it’s not like this movie is afraid of rethreading old ground.

To be fair at least that made Palpatine’s retconned connection to both Rey and Kylo more sensible, if he had been secretly cultivating this dyad for years as his ultimate goal. Tough I prefer the idea that the dyad is something new that has formed between them sometime during or after TLJ, as implied by the change to Kylo’s line, and with that change it makes more sense that Palpatine wouldn’t know of it.