Probation officers don't like people who are on probation to lose their jobs. I would venture that there is a reason the probation officer wanted your nephew to do the additional counseling, whether or not you believe it was necessary. If he lives with minors and his probation forbids that, they are within their rights to enforce his probation and make him move. If he violates his probation he can be sent to jail or prison, depending on his sentence, and they can tell him that.