No, because Mew doesn't evolve into Mewtwo, and Mewtwo precedes Mew in the Dex.
It doesn't matter. Mewtwo is called "Mew-two" even if it is just the clone of Mew. If they want to they can create a another, a lost clone - the legendary Mewthree, lol.
I just want to say some pokémon really don't need to exist.