Honestly, I'm relieved to hear this. I love King of the Hill. It's one of my favorite animated shows ever.
But I really don't think it can exist in today's entertainment landscape and be what it was. I think it would be a neutered shell of its former self. Part of the charm and a lot of the humor was how unapologetically un-P.C. some of the characters were.
It just wouldn't fly now. It was a product of its time--a snapshot of that era--and maybe it's best to leave such things in their proper time and place.