Originally Posted by Square Enix
Thief employs a unique set of Abilities, but also relies on the party to bring out its full potential. This is the form Thief will retain, but expect new variations where instead of matching the pace of the party, the Thief will instead be able to direct the flow party through the use of its techniques. This will include new ways to manage Enmity, allowing the player to more freely raise and lower Enmity and avoid dangerous situations. For endgame content, the Thief may also be improved to deal out more damage. The Community Team Twitter also indicated an enhancement to Treasure Hunter and a new Steal Ability could be in the works.