The bean counters will be much more rational than that. Is it cheaper to fly X people east to DTW and fly (X+Y) people west to Podunk, or to fly X people east to MSP, Y people west to MSP and (x+Y) people west to Podunk? The larger X gets, the more MSP is likely to keep the connection. If Y get too small, DTW loses its connection.

If they do shift too many flights to DTW, that will open up gates in the main terminal and they might find ATA & Sun Country moving from the Humphrey Terminal back into the public view. Excess gates will also be an incentive for other players such as Southwest, Jet Blue, and Virgin America.

Those who think MSP will be demphasized as an international hub simply don't realize the extent of industry (esp. high tech) here. Back in mainframe days all of the BUNCH (Burroughs/Univac/NCR/Control Data/Honeywell) were either headquartered here or had major R&D divisions here. Seymour Cray (the legendary supercomputer designer) worked here for NCR, Univac and Control Data before founding Cray Research in Chippewa Falls, WI (where he had moved his CDC team several years earlier). IBM has a large facility an hour south in Rochester, where the Mayo Clinic is located. Although the mainframe days are long over, the companies and their employees have evolved into modern firms and created countless spinoffs in the region. The company I work for is a Fortune 500 company with plants and divisions in both Asia and Europe.

Best Buy as a large new headquarters campus about 5 miles west of MSP. USBank, Wells Fargo and Cargill (now part of a larger British firm) are all here. If you need a pacemaker after reading all these merger threads, it probably came from Medtronic. And the list goes on ....

(And if you're wondering which building was the Control Data HQ, look to east when you're taking off or landing for the Building with the Health Partners name on the side. In CDC days the windows had a goldish tint and we knew it as the "Puzzle Palace".)