MTG Salvation

9/29/2017 If Kitesail Freebooter leaves the battlefield before its enters-the-battlefield ability resolves, the opponent will reveal their hand, but no card will be exiled.

9/29/2017 The exiled card returns to its owner’s hand immediately after Kitesail Freebooter leaves the battlefield. Nothing happens between the two events, including state-based actions.

9/29/2017 In a multiplayer game, if Kitesail Freebooter’s owner leaves the game, the exiled card will return to its owner’s hand. Because the one-shot effect that returns the card isn’t an ability that goes on the stack, it won’t cease to exist along with the leaving player’s spells and abilities on the stack.