Yes, all the time and am very familiar with the market. I personally listen to a number of DFW stations every single day.
Memphis is 47% black and DFW is 17%. That is not a small difference in market makeup. The only markets with a larger black percentage are Albany, GA and Jackson, MS (iHeart's gospel station is #1 12+ in Jackson!). Memphis also has a great deal of history of black radio.
Because DFW is such an enormous market there are actually more black listeners here than in Memphis, but the key here is relative to the market 's overall makeup. If DFW was 47% African American, I suspect there would in fact be at least one rimshot carrying black gospel, despite the demographic problems already discussed, but because of the makeup, other formats have proven to be more viable or desirable for growth.
You will see that in Memphis, which is 5% hispanic, there aren't enough ears to support multiple and competing spanish-language formats like in Dallas. Instead you've got an AM that is primarily pushing their 99 watt translator.
Finally, there is and always has been a grand debate on if Texas is actually part of the south or the southwest or something else or it's own separate thing. The truth is Texas is a giant and very diverse state with many differences from region to region. Beaumont and Lufkin, for example do feel very southern to me. Lubbock and El Paso? Not so much. San Antonio and the RGV are not southern in any meaningful sense other than having lots of warm, friendly people. While there certainly are some southern sensibilities in Houston, there are also all kinds of other sensibilities as well.