In hindsight, MLB should have chosen Orlando instead of Tampa Bay for an expansion team, but maybe the proposed Orlando ownership wasn't as financially strong.
Demographics make all of these potential MLB markets problematic. None of them are particularly large; Orlando has the largest media market among them with
about 1.5 million TV homes. Las Vegas is an even smaller market than MLB's current smallest markets, Milwaukee and Cincinnati.
MLB has made relocation more complicated by foolishly giving most teams local TV rights outside their home markets, which gives some teams incentive to try to block relocation into "their" TV territory. Any of those teams might demand money as compensation even though a relocated team is still hundreds of miles away.
Examples:
-- Mariners would lose Oregon from "their" TV territory if a team moved to Portland.
-- Reds and Braves are both televising "local" games in the Nashville market; Braves also send games into Charlotte.
We won't know for sure unless/until some metro area steps up with the money for a new ballpark, but if there was competition and other clubs raised a big stink about compensation, it might make it easier to get a Rays move approved for Orlando or Montreal than other places.