It's best described as compulsory (re)education for at-risk adults. And it's also successfully concluded; the schools have been closed for over four years.

Westerners have settler-colonialism in their cultural DNA. When they see boarding schools for ethnic minorities, they can't help but project their own genocidal history and intent. But it's not a fair comparison. Schools for First Nations people in North America would beat children for speaking their native tongue, whereas the ones in Xinjiang improved literacy in the indigenous languages.