I think you're right. I did a day trip down across the state line into Georgia from Robbinsville a couple of months ago when riding in the Smokey Mountains. That area around Vogel State park and Suches GA has some outstanding roads. Well worth the ride down there if you're at the tail of the dragon for a few days.
It does appear to be US 129; much nicer to ride that road in the daytime (like the video) as opposed to night-time. I was there about 9 years ago (two different occasions); riding it southbound at night is not as much fun as it's all downhill and the headlights don't light around curves. The advantage of riding that portion of US 129 at night is that there isn't any traffic (including police).