So will it impact China's growth? The international financial implications of Evergrande going under may be limited since most of its debt is domestic. Still, there will be second round effects. If it's the free flow of credit that has helped to sustain China's rapid growth, especially after the international financial crisis of 2008. Tighter credit norms must affect the peace of Chinese economic activity and therefore of the larger global economy. This could mark the end of the long run of "miracle" growth that has made China.
When you talk about Chinese economic growth or their economy in general you have to keep in mind that the system there is not the same democratic capitalist nonsense. It's different which is why some economy experts claim that China already had the growth they wanted to for now and they are shifting their attention to improving people's lives by closing the gap between different classes.
If you look at the past 40 years you can see that in China they eliminated absolute poverty (from 85% down to 0%) meanwhile it all those democracies with capitalism the gap is increasing fast as the poverty spreads, number of homeless families increase, quality of life deteriorates, ...