I suspect any remaining changes for January will be minor, but as others have said I see this a feature not a bug. I dont like DL and only fly them when there is a very significant price and/or sheduel advantage but they are great about making changes after shedule changes. Last weekend I had a 1.5 hour change to the outbound of a trans Atlantic flight and not only did they allow me to change the outbound to anything I wanted, they allowed me to change the untouched inbound to an itinerary that eliminated an overnight stop and was 4 times the price when I was ticket shopping.