Yeah boarding schools aren't re-education camps. How they relate is that supposedly children with both parents detained get put into orphanages or boarding schools (according to research from Zenz). In this case I'm inclined to believe the claim as it makes sense that children in these circumstances can't just be left alone. It also doesn't seem to be that big of deal since at least from the sources I've seen, people in the re-education camps maintain regular contact with family members remotely.