>Second link: apparently no slavery either. Just training ex inmates.

Not training them, using them, for very difficult and even dangerous labor. And paying them well below subsistence wages to do it. That's slavery by the definition of international labor standards organizations.

I have little doubt that China's system of labor camps uses pretty similar incentive structures, the inmates are probably paid a tiny pittance, less than 10 or 20% of what local free laborers would be paid, but still not quite zero. IIRC, even the Soviet gulags often paid their inmates a tiny nominal wage. That is not a defense of them, they were grotesque inhuman death camps, a system of slave labor on a scale almost unprecedented in human history.