What did the spoilers say? The BRAND NEW FOOTAGE was just aired - Jack explaining the other survivors were Boone (suffered tremendous internal injuries and died after a few days), Libby ("didn't make it through the first week"), and Charlie (drowned a few weeks before they were able to leave). It makes sense to use them in case their bodies are ever discovered, but that wouldn't explain the bodies of Shannon, Nikki, Paulo, Ana-Lucia, or Scott, who were all buried in the same makeshift graveyard as Boone & Libby, not to mention other bodies buried around the island.