You mentioned Colorado, and I implied Colorado and others that have followed suit, in my earlier comment which I assumed that you read before you wrote this reply.
Your #1 source does not mention the text you attributed to it. And it's an opinion piece. It mentions that the inmates who volunteer to work do so for low wages. Well, they could also choose not to work on those programs. What proof do you have that they were coerced (I'm actually not arguing against it, but looking to correct my opinion if necessary).
In any case, states do things that the federal government does not agree with all the time (legal weed, for one). It's a crucial feature of our system of government.