No. It isn’t. And by saying so I’m not sure you get what the concentration camps (and gulags, the Russian versions) were all about. That would take to long to describe here but their horribleness was not an issue of lack of supplies or separating families. Or put it this way: in these refugee camps, when somebody dies, it makes the national news. Now, nobody should die; that’s an awful thing. But in a real concentration camp (not a death camp) death is a daily occurrence.
As for AOC, I believe that by making this comparison she was deliberately trying to sensationalize what is happening at the border. Beyond the fact that this is, IMO, unnecessary, as I wrote I think it hurts rather than helps. That is because, as a general rule, the key to winning almost all political debate in this centrist country of ours is to be able to place yourself as reasonable and your opponent as extremist. AOC, by making such comments, is allowing conservatives to paint her, and by implication other liberals on this issue, as extremist.