I doubt ABC had anything to do with it, it was most likely your local ABC affiliate that was going to air the Dukes as it was not scheduled to air on my local ABC affiliate.
I miss TNN as well though not for the country music, more for the weekend fishing shows and car shows and racing.
When you look at the many ways rock music has split in 50 years country music hasn't done much except drop the western in county western. I think it's due for a split though. They need to label some of this stuff county-pop and get it off the radio stations that are calling themselves country. If you want to call yourself country you need to stop playing some of that stuff. Folks like me have stopped listening.