Are you flying FC or Y? As you know, DL as other airlines can and will change aircraft at anytime. Maybe they are planning on changing the aircraft, who knows.

Now with that said, using your info, I just priced out a one way FC ticket for flight 1354. Departs LAX at 10:45 PM, arrive ATL at 5:58 AM. When I click on the "Details" tab, the next screen shows various info including the aircraft. In this case, the A330-200. When I hit the "View Seats" tab next to the aircraft, the seat map comes up showing FC and coach for an A330-200.

The thing is, DL flies all sorts of aircraft on this route. Unless that plane has to be in ATL, they could do a aircraft swap to accomodate the lack of passengers. With that said, the available seats on that flight look slim. So, I would imagine you will be on the A330-200.