And everything else is still canon, in its own timeline, just comprised of stuff that's not going to re-happen in the Abrams timeline. That comment might not be saying what you think it's saying, though. Note that the commenter claims "the jj-verse was a different universe before Nero interrupted the timeline" but then goes on to say "it was the Narada’s interference that caused the change between the two formerly identical universes". In other words, the "different universe" that Nero went into was, until his arrival, a carbon copy of the Prime. As such it's a distinction without a difference: going into the past of a carbon copy of the Prime and creating a branching timeline/universe by going into the past of the Prime really amount to pretty much the same thing.