I am working from the assumption that aluminum bats would hit a person in much the same manner as they would hit a baseball. Aluminum bats are banned from major league baseball because the spring effect of the metal causes balls to go faster and farther. I imagine the same spring effect would cause more damage to a person hit with an aluminum bat.
But yes, I agree that whether the person is hit with a wooden or aluminum bat there is a chance of them dying.
The deformation of the aluminum bat leaves it in contact with the ball longer, and the spring action transfers more energy. A human head will deform more easily than a baseball; blunt impact injuries are a function of momentum over time, so a bat that deforms on impact would do less damage. Any baseball bat can be used to kill by hitting people in the head though.
But yes, I agree that whether the person is hit with a wooden or aluminum bat there is a chance of them dying.