Naomi said two things in particular that really got me thinking. One was that the entire plane had been found with all of the bodies, as confirmed by robotic cameras. Leaving aside the question of how searchers even found the crash site when the plane was underwater and a thousand miles off course, it strikes me as improbably convenient that they accounted for every single body. Naomi's other intriguing comment was that discovery of the wreckage prompted a huge memorial for Charlie and the release of a popular greatest hits album by Driveshaft. Finding those bodies apparently affected a lot of people. Charlie's death was felt worldwide, but the same was undoubtedly true on a smaller scale for everyone else aboard. Funerals were held and folks moved on -- all thanks to the closure those bodies provided.
That reminds me of John Varley's science fiction novel Millenium, which was also made into a B-movie starring Kris Kristofferson and Cheryl Ladd. Two planes collide in mid-air, falling to Earth in a fiery crash that kills everyone aboard. When FAA investigators recover one of the cockpit voice recorders, they discover something strange. Even though the fire didn't begin until after the planes had crashed, a crew member is heard screaming that all of the passengers are already dead and burned. It turns out that time travelers from the future have been abducting people from doomed airliners and replacing them with dead duplicates. The cryptic comment on the voice recorder was because the passengers had been abducted and replaced with burnt corpses in anticipation of the crash.
The reason for taking people who are about to die is that the dead have no future. Changes to the past create temporal paradoxes that ripple through spacetime, causing future "timequakes" as the timeline shifts to compensate. Millenium's timequakes strike me as an interesting metaphor for course corrections, though I doubt the latter are similarly physical. My guess is that course correcting more closely resembles the effects of the temporal "Change War" in Frtiz Leiber's sci-fi classic The Big Time. The premise is that two time-traveling factions (the "Snakes" vs. the "Spiders" -- the rest of us are "Zombies") are locked in combat with all of history as their battlefield. They strike at each other by intervening to change the outcome of key events along the timeline. Here's how one character describes the Change War:
Have you ever worried about your memory, because because it doesn't seem to be bringing you exactly the same picture of the past from one day to the next? Have you ever been afraid that your personality was changing because of forces beyond your knowledge or control? Have you ever felt sure that sudden death was about to jump you from nowhere? Have you ever been afraid of Ghosts -- not the storybook kind, but the billions of beings who were once so real and strong it's hard to believe they'll just sleep harmlessly forever? Have you ever wondered about those things you may call devils or Demons -- spirits able to rage through all time and space, through the hot hearts of stars and the cold skeleton of space between the galaxies? Have you ever thought that the whole universe might be a crazy, mixed-up dream? If you have, you've had hints of the Change War.
The part about the "Ghosts" of people from timelines that no longer exist makes me think of Jacob and the Whispers, both of which have a ghostly quality. I could easily see them being the remains of people who were "erased" from history, perhaps by the original Incident. I'm also struck by the reference of "spirits able to rage through all time and space" -- many, myself included, have speculated that Desmond's electromagnetic "soul" time traveled into the past during Flashes Before Your Eyes. This jibes with the Others' brainwashing video, which states that "only fools are enslaved by time and space." It also fits with Ms. Klugh's question about whether Walt had ever appeared someplace he wasn't supposed to be. Unbeknownst to Michael, Walt had done so on at least two occasions, haunting Shannon with his apparition.
I think the fabricators of that second plane were afraid of becoming ghostly victims of "lost time" themselves. The failure of Oceanic 815 to crash -- and, more importantly, to be found -- threatened to send ripples through the timeline, profoundly unsettling the future. Yes, the universe would ultimately course correct, as it did in the case of Charlie. But the overall picture might still be fundamentally different, as Desmond's changing flashes of the future tend to suggest. So they staged a plane wreck off the coast of Bali and stocked it with duplicates like the ones in Millenium -- perhaps even cloned from those missing hairbrushes that Claire mentioned back in S1. Family members of our Losties gained closure and fans of Driveshaft got their greatest hits album. The rest, as they say, is history...