when asked how long has the flash sideways been planned:
Lindelof -
" It’s been in play for at least a couple of years. We knew that the ending of the time travel season was going to be an attempt to reboot. And as a result, we [knew] the audience was going to come out of the “do-over moment” thinking we were either going start over or just say it didn’t work and continue on. [We thought] wouldn’t it be great if we did both? That was the origin of the story."
Cuse - "You can just watch the flash sideways — they stand alone all by themselves."
Lindelof - " What we’re trying to do there is basically say to you, “God bless the survivors of Oceanic 815, because they’re so self-centered, they thought the only effect [of detonating the bomb] was going to be that their plane never crashes.” But they don’t stop to think, “If we do this in 1977, what else is going to affected by this?” So that their entire lives can be changed radically. "
So this stuff has already been well established -- The LAX Bizzaro world version of things is a thought experiment of "WHAT IF."
But the next thing that caught my eye was this:
Cuse - " The archetypes of the characters are the same and that’s the most significant thing."
He's saying that there are aspects of the characters that are the same, but it is not the same person. This is a really minute distinction, but it denotes an important way of thinking about the characters on the part of the writers. Kate in Bizzaro world is not the same Kate on Craphole Island. You could have said that is the same Kate -- just in different circumstances, but this is not what Cuse is saying. Cuse is endorsing the idea that a person is the sum of the choices that they have made and the experiences that they have had. That sum has created an entirely different person -- they share certain "archtypal" characteristics, but they are not clones. They have different thoughts and personalities. They would probably have quite different responses to identical problems. They might not even like one another if they met.
and finally
Lindelof - "we don’t use the phrase “alternate reality,” because to call one of them an “alternate reality” is to infer that one of them isn’t real, or one of them is real and the other is the alternate to being real."
CUSE - "But the questions you’re asking are exactly the right questions. What are we to make of the fact that they’re showing us two different timelines? Are they going to resolve? Are they going to connect? Are they going to co-exist in parallel fashion? Are they going to cross? Do they intersect? Does one prove to be viable and the other one not? I think those are all the kind of speculations that are the right speculations to be having at this point in the season."
LINDELOF - "These questions will be dealt with on the show. Should you infer that the detonation of Jughead is what sunk the island? Who knows? But there’s the Foot. What do you get when you see that shot? It looks like New Otherton got built. These little clues [might help you] extrapolate when the Island may have sunk."
So
They are drawing attention to the idea that there is a sunken island in Bizarro World, but not in the other timeline. Lindelof at the end there is drawing explicit attention to the fact that the Island in Flocke's World is pretty much the same.
If I had to guess, I'd say he's hinting that the bomb going off sunk the Island, and therefore if the Island is not sunk in Flocke's World, maybe the detonation didn't happen in that world. Juliet said "it worked." This probably indicates an awareness on her part that the detonation did happen, in 1977, and Bizarro World is the aftermath of that event.
The mystery (according to Cuse) is how do the two timestreams intersect. It did not appear that the Bizarro World Locke and Shephard knew each other at the airport, so it's probably also safe to assume that Jack doesn't remember Locke dying, probably because that Locke didn't.
Apparently, "our" Sawyer and Juliet blew up Jughead in the 1977 of Bizarro World.