That would keep another station from using it - in Georgia. I wonder if anyone has ever taken a U.S. trademark, tried to use it in Georgia and been prevented from doing so, and then challenged the decision on the grounds that they held the national trademark? As you aver, CC didn't get where they are by leaving anything to chance. I doubt they'll surrender the service mark or just let it expire. They will sit on it and maybe use it in the future.
WPEH in Louisville has been using Peach in their corporation and radio identity since 1960. The corporate ownership is in the name of Peach Broadcasting.