The Memphis situation should be a good warning case.

The owners of the Grizzlies didn't want to be in Vancouver, never build up a relationship and then left for Memphis. Now Vancouver is a thriving city, with a large market and is thinking about bringing another NBA team again.

Meanwhile the Grizzlies are dying in Memphis, with a very small market and they are losing money. Very soon they also will try to relocate somewhere else.

The same will happen again in OKC in 5-7 years when the fashion of the 'new team' wears off. In American Sports leagues where there is no relegation, teams simply have to be based in the largest markets because it's the only way it makes sense.