If the boys are in protective custody, I would think they would prefer to put them with relatives rather than foster care. I would think the county would find it appropriate to place them with the Coxes, even if it is "temporary," although we don't know the reasoning behind the removal from the home. Since Josh has not been charged, and daddy is in jail, why would they be removed, unless the expect daddy to be home shortly, or there is evidence Josh is also involved in this perverted business.
So, I hope the Coxes get a phone call asking them to come pick up the boys--after some child crime experts get a chance to fully and thoroughly question the boys as to all the goings on in their lives over the past couple years. See what they remember first.