I think there is a reason why we saw Jacob get killed before the bomb went off. Changing the time line doesn’t just rescue Daniel and Sayid.
Jacob was probably visiting the Losties because he needed them so he himself could be saved.
hmmmm...I’m confused as to how an H-bomb saves Jacob - but I’m game!
Since Jacob seems to be playing the role of Jesus being betrayed by a chosen follower - then I’m ready for an easter ending here!