Then life wouldn't exist. The Phoenix is the totality of ALL life. Remember when Galactus tried to remove it from Rachel? Stars died. And that's just Rachel.
And how is the Presence involved, but not TOAA? Isn't that a little one-sided? Especially since you're talking about two different universes. TOAA is going to say, "OK. I'm okay with destroying all of my creation." That's a little weird.