Microsoft just documented the new policy setting for Microsoft Edge. These settings can be configured via both MDM and Group Policy. To get use the policy settings you need to be running at least Windows 10 Preview build 17718. Then you can then install Group Policy management Console (now part of Core OS) and trial the new Policy settings.
For a full list of policy settings and documentation check out https://docs.microsoft.com/en-us/microsoft-edge/deploy/new-policies