Another Star Wars: Rise of Skywalker trailer has arrived, but nothing has yet disproved this theory of where Rey began and where she’s headed. In fact, in light of the history of misdirection in Star Wars trailers, hearing Palpatine’s voice say “your coming together… is your undoing” suggesting that Rey and Kylo Ren uniting against a common foe actually points to it meaning something completely different. It could, for example, mean that Rey and her fellow clones meeting is what Palpatine had planned… ever since his previous plan resulted in him being tossed down a garbage chute.
Source: IGN.com Does Palpatine's Warning Hint at Rey's True Origin?