What makes you think the case was closed? If he was taken into custody, it means there was an outstanding warrant for his arrest and I don't see a Judge releasing him on OR. You need to hire an attorney.
You need to hire an attorney immediately. The Judge is going to have a hearing to determine whether you boyfriend violated the terms of his probation. Based upon your question, the answer is probably yes. The Judge will then be able to re-sentence your boyfriend to a new term of probation or inprisonment up to the legal maximum sentence allowable.
Whether he comes home or not is up to the Judge. There are many factors that can effect that. What was his original charge? Why has he not kept in touch with his probation officer? Have all his fines and costs been paid off? Has he gotten into any other trouble? He is employed? Does he support any children? He needs an attorney to help him with this hearing to get the best possible outcome.