Back in 2005, J.J. Abrams promised that one of the most popular theories about Lost was not true. In 2006, Damon Lindelof did the same. They were so convincing in their denials we even guessed that this theory was one of the eight greatest probably wrong theories about Lost. Well, spoiler alert! It turns out a J.J. Abrams–Damon Lindelof promise is only kind of good!
We're sure in the weeks to come, there will be lots of discussion about the distinctions between "purgatory" and "heaven," and "the afterlife" and "being dead," and "misleading information" and "flash sideways is not the island," and "when did the Lost creators actually know how the show was going to end" and "why didn't Darlton care at all about the show's mythology?!" — but in the instant aftermath of the finale, it seems that something sort of like purgatory, insofar as purgatory is a place full of dead people, did in fact have something to do with this here series called Lost.
With this in mind, watch J.J. Abrams tell a crowd at the Paley festival, "Well [the theory] that I like, and the one that everyone was talking about a while to me, is the purgatory one, and though that's not what it is, it is such a great idea ... But that isn't literally what [the island] is."
And then read Lindelof say, "People who believe that they're in purgatory or that they're subjects of an experiment are going to start reassessing those theories based on the fact that we are literally showing you the outside world."
Sure, Abrams and Lindelof weren't totally lying: The island itself was probably not purgatory! But the finale did involve afterlife issues in a more fundamental way than either suggest. So, all of you, the ones who watched the first episode of Lost and said, "Hey! I bet this is purgatory" and then spent the next six years fighting with people about how you were still right, even though no less than J.J. Abrams and Damon Lindelof said you were wrong? Well, you were sort of wrong, but not as wrong as other people! So, sleep well, and dream of dead soul mates holding hands in a church.