I suppose along with new ways to opres slaves there will be options to emancipate and\or free them, maybe gradually. So We'll have a transitionary options like indentured servants, whom you can buy.
Should food be reworked, some starvation can be solved by offer from Enclaves to save your starving population via indentured service, renting them to other empires with possability for them to return back(or stay in other empires if their happiness there will be high enough)