I should mention I have nothing but respect and best wishes to non-native English speakers or those with African accents and I've met some who were great teachers but in the case of Training Centers as well as private schools one of the main ideas is that the kids or adults practice with a native English speaker to hear and emulate and practice sounding American/Canadian/British/Aus

Its not like Nanning was a backwater where there were no native english speakers. In fact, I remember lots of them about 1 or 2 years ago when I visited and now almost every single one of them is gone. a handful of a church group and a few retirees (in common is they arent here for working).

But in addition to all the other scams in Nanning, the reports and what I've seen its surely a sign when native english speakers (the most in demand) are leaving.