SPOILERS
You know what we should be really asking ourselves about the sideways timeline?
If the island is underwater, what the heck happened to Jacob and the Man in Black?
I don’t think we’ll find out until later, but my suspicion is that since The Island is underwater, the Man in Black is now back “home”, and whatever that means, it can’t be good.
If I follow you…which I’m not sure I do…you’re saying in the LAX timeline the Man In Black has escaped/returned home and that may have some impact on the LAXers?
Yes. Since in the LAX timeline the island is underwater, something happened to Jacob and the Man in Black. Whether they escaped, or both died, I think it has an impact not only on the LAXers, but also the world.