The Confederates picked up the rails between Monroe and the west bank of the Mississippi and I think relayed them in Marshall, TX. If so that was telling about what they thought on the chances of re-establishing cross river communication.IMO the largest downside to the Confederacy of the surrenders of Vicksburg and Port Hudson was that 100,000 Federal troops could be otherwise employed. It also simplified travel on the Mississippi River for Federal shipping.
By 1863 I don't see much Confederate advantage to holding the positions. Shipping supplies across the river from the Trans-Mississippi requires the ability to receive items on the east bank and forward them for distribution to the rest of the Confederacy. That capability was gone.