Sadly, I can't see why it would ever fly again. One reason is there is no O&D traffic out of RDU. It was a good hub for connecting traffic but even for a hub there needs to be some O&D traffic to supplement connecting traffic. American's hub in RDU suffered the same fate. Now, Southwest is embedded in RDU and no one has any desire to go up against them head to head.
I have to disagree with that. RDU
has great O&D for a city/metro its size. It has higher O&D than many hubs/focus cities including: Nashville (SW focus), Indianapolis (ATA), Pittsburgh (US), Charlotte (US), Milwaukee (Midwest), Cincinnati (DL), & Memphis (NW). It also has higher O&D than non-hubs like: Hartford, Austin, San Antonio, Columbus, Providence, Ft. Myers, Albuquerque, Jacksonville, Reno, Norfolk, Buffalo, etc.
That being said, I don't think there's any hope of Midway flying again.