Any station in a market can claim syndicated exclusivity and get a particular program blacked out on the superstations. Even though they could simply black out an individual show DISH generally just does not sell the affected superstation in that market. Even though the CW and My Network TV is not technically syndicated it works the same way. In addition a local station can claim it for the non prime time programming (e.g. Jeopardy or Wheel of Fortune).
Surprisingly very few local stations demand this. But one or more in Houston may have.