The MCI reconfiguration would involve changing the passenger facilities and accesses completely, not a mere remodel, and in some of the proposals simply building a completely brand new terminal complex and eliminating the existing ones.
(Another reason for the change: Security. The original MCI was designed before checkpoints, for you to be dropped at the curb virtually right in front of your individual gate. As it stands today you have to have separate checkpoints for as few as 2 or 3 gates with the restrooms outside the secure area.)