Yes, I realize that producers have claimed they always had the end game in place. And I'm willing to concede that, early on, they decided Jack was going to be dead and not know it. After all, they wanted to kill him in the first ep.
i'm not sure if i'm reading you correctly, but i don't think they gave us a story of the characters being dead or in purgatory.
i think seasons 1-5, and the island portion of season 6, happened. everything happened as we know and saw it. it was only the "real world" portion of season 6 that was the purgatory - a dream world created by all of the island-relating characters, connected by their friendship and love and similar gay emotions.
we saw jack die on the island, and it was his ghost roaming "earth 2" trying it's best to figure that out. he wasn't dead the whole time, he died in the finale - we just got a few weeks' worth of seeing his deadness. in other words, they weren't "flash sideways" sequences at all - they were distant flash forwards, years (or centuries) after the characters' actual deaths, that the souls of the island folk created where they could meet up. like the local bar after work, except for ghosts. it looked and acted like 2004/2010, but paraphrasing what christian said, it was a point without time.
There was a scene of the Island UNDER WATER at the beginning of season 6. Why would this exist in purgatory?
my opinion; the purgatory world the losties created was based on a world where the bomb exploded and reset time. it gave them all a familiar "starting point" in their reboot.
Juliet confirms that "it worked" meaning the bomb exploded and an alternate reality was created.
again, my theory - it did; they created it.
Desmond saw bits of the alternate reality. His 'power' was time travel, not seeing dead people.
hah. who the fuck knows what desmond's power was? he could withstand energy bursts, time travel
in! his! brain!, occasionally get glimpses of potential prophetic futures, etc. all we know is he had a thing for seeing other things.
Sayid had a fling with Shannon. He spent his life pining after Nadia. The writers told us over and over she was his true love. Then, in the final season, we're led to be believe it was really Shannon all along?
everyone's purgatory moment related to their island life.
In a similar vein, if being with your true love allows you to remember and pass on, then Rose and Bernard should have been long gone (or at least far more aware of the fact they were dead then we led to believe).
we only got... what, a week's worth of "earth 2"? if all the bits were taped together? as they were shown in the church in the end, they clearly met with and remembered one another. and, potentially did so without the helping hand of desmond, hurley, or charlie.
Why are there new characters in "heaven" reality? You're not gonna convince me that Jack's kid was just another creation of fantasy
well, why not?