The problem becomes differentiating between a novel and a setting. My issue with Dragonlance was that after the War of the Lance, the setting became less interesting; same with Dark Sun. They make for great reading material, but it's hard to translate it into a workable setting. Realms managed to do this for a quite a long time, probably because it was originally a setting for stories rather than as an RPG setting.I am coming to think every metaplot eventually reaches the point where a consensus of the devoted fans go "nope, I'm going to just ignore that and act like that never happened."
My World of Darkness-playing friends pretty much ignore The Reckoning, for example (unless the plot of the game is specifically Gehenna/Apocalypse/end-of-the-world scenario).
Sometimes a metaplot isn't in the settings best interest. Greyhawk was never meant to have a metaplot, except as expanded by modules (adventures), but TSR changed that with the success of the Realms. I don't think Eberron has a metaplot either. I didn't think Mystara had one, but I hadn't heard about Alphatia (was it an adventure?).