And most media called them detention centers under Trump as well. You're mistaking social media posts for news posts, I believe.
https://www.google.com/search?q=trum...hrome&ie=UTF-8
Not many hits of media actually calling them that (though they do discuss the topic), eh?
https://www.google.com/search?safe=o...39.52UZe8pQ80Q
Yowza, look at all those hits of media referring to them as detention centers!