I'll believe it when I see it. The end-times of China's growth is like a broken record, except it goes dormant for a few years at a time.
Their debt crisis is pretty bad but not insurmountable in a country where the government controls more than 50% of the banking infrastructure.
The main problem they face right now is a crisis of confidence in their consumer market, this is decidedly easier to fix with mechanisms that won't re-inflate the property bubble.
Demographic shifts sure. Because similar to Japan they have net-zero or even net-negative immigration they will need to fix that internally but it's a 10-20 years out problem, not a now problem.
For now I'm in wait and see mode. China has more powerful tools than other economies to correct these sorts of problems so there is a good chance like 2015 that this blows over too.