Re-education camps are certainly a human rights violation; however the important difference to concentration camps is that people are expected to leave the camp alive once they have undergone the re-education. If the Chinese government has some foresight, there'll be some actually useful education beyond regurgitating propaganda and the inmates might end up with decently paying jobs afterwards. Someone with a stable income and a family to feed is less likely to throw it all away to join a terrorist cell, so that would achieve the stated purpose of the camps.

On the other hand, a large-scale government action completed in short time usually indicates that things haven't been thought through all that well. If all they're doing is putting a bunch of Muslims into an adversarial situation with probably racist guards, I'd expect any actual terrorists among the inmates to have no difficulty finding recruits.