It took us a long time to realize that Mila Kunis wasn't the original voice of Meg Griffin. If only for the fact that, like the other characters on the show, we don't pay attention to Meg. God, shut up, Meg. When we finally did realize that there was a different voice before Kunis—Lacey Chabert—we desperately went searching for gossip. Did Chabert have a falling out? Was she a diva? Did Kunis swoop in and claim the spotlight?
No. It was a contractual thing. Creator Seth MacFarlane said there was a mistake on her contract and that she didn't intend to stay for the full run of the show. She wanted to go, and the team was cool about it. We guess it's only fitting that the gossip behind this story is so boring, just like Meg.