Its hard to say. They moved their headquarters from East Point Michigan to Ft Lauderdale about 3 years ago.
I dont think that they would dramatically increase routes because I think the new terminal isnt really going to expand in size, it would just be brand new. the last i heard the new terminal would only be 23 gates, but the master plan calls for something like 50. I think the current terminal has about 23 or more gates now, remember, Spirit is actually using what was the Davey Terminal in Concourse C and they have at least 6 gates. Delta though will probably be giving up a couple gates by then since they are moving to Mac.