When Nero and Spock travel back to the 2330s and destroys the USS Kelvin, the timeline diverges. From TNG’s “Parallels”, it can be interpreted when a timeline diverges it creates a parallel universe. But what if the Abramsverse is a preexisting parallel universe that was mostly similar to the main trekinverse up until Nero and the Narada appeared in the 23rd century? Though I’m satisfied with Bob Orci’s explanation of the timelines diverging and co-existing, a pre-existing Abramsverse prior to Nero would give writers greater flexibility on certain events like the Eugenics Wars. In TOS and TWOK, it’s explicitly stated Khan and his minions fled earth on a sleeper in 1996, which would also be true if the Abrams Trek timeline diverged from the main Trek timeline in the 23rd century. If the Abramsverse existed prior to Nero, the Eugenics wars or other earth events can be moved up or changed.