Picard's parents could easily still create Picard, and so forth.
: this reminds me of the joke/rumor that the drill falling on SF crushed a Picard ancestor.
) Abrams' time travel is no less deterministic than what we've seen before. The thing is, there's no way to know exactly how the changes in the timeline will influence things, so the writers have a somewhat free hand. Though I agree it would seem highly unlikely if all the significant TNG era characters turned out almost exactly the same.