Yes, seeing is believing. There are direct flights from Chengdu to Daocheng. According to Wikipedia:
Daocheng Yading Airport (IATA: DCY, ICAO: ZUDC) is an airport serving Daocheng County in the Garzê Tibetan Autonomous Prefecture of Sichuan province, China. It is located in Sangdui Township, 50 kilometers north of the county seat and 130 kilometers from the Yading Nature Reserve.
Situated at an elevation of 4411m, it is the highest airport in China! Yes, Yading is going to turn into another Jiuzhaigou – inundated by loud, spitting, littering local tourists. But the first thing that came to my mind is that people are flying into a 4411m airport from a 500m airport in Chengdu. Altitude sickness is going to be a major issue. Has anyone thought of that?
Anyway, I’m seriously considering taking the flight back from Daocheng.