I'd really disagree with this. Essay writing forces a person to think critically. You have to construct an argument for or against something. Even if it's echoing source material or a teacher, you still have to think in a way that other testing formats do not.
By offloading this to a machine the students are undercutting themselves more than anything else. They'll be less effective communicators and less capable of disagreeing with ideas and concepts the face in the real world