Originally Posted by jsloan

If you are talking about the January 3 ORD-HNL nonstop flight, the economy class seatmap is wide open. There's no overbooking here.

As noted, if you view the seat map from within your reservation, you will see an X in all seats that are not in your cabin. UA assumes you only care about flights in the cabin you're booked in. If you view the seat map from the purchase flow, as if you were buying a new ticket, you see the complete seat map. The front is nearly full, and the back is nearly empty.