iOS 9.3 is currently in BETA and should be released in the coming weeks, however from the Developer Reference guide (publicly available) we can deduce some of the new controls we will have from EMM/MDM solutions, here are the interesting ones currently listed. It should be noted that more could be added or these could be removed/changed before release date:
Home Screen Layout Payload
This payload defines a layout of apps, folders and web clips for the Home screen. It is supported on iOS 9.3 and later and requires supervision.
Education Configuration Payload
The Education Configuration Payload defines the users, groups and departments within an education organisation. It is supported on iOS 9.3 and later and requires supervision.
This payload specifies the restriction enforced notification settings for apps, using their bundle identifiers. It is supported on iOS 9.3 and later and does not require supervision.
Shared Device Configuration Payload
This payload allows admin specify optional test displayed on the login screen of lock screen (ie. If lost, return to” and asset tag info. It is supported on iOS 9.3 and later and requires supervision.
Managed Safari Web Domains
Opening a document originating from a managed Safari web domain causes iOS to treat the document as managed for the purpose of Managed Open In. This already existed, but the new feature is that you can whitelist domains that may store their passwords in Safari.
New iOS Restriction Settings
allowRadioService – Requires supervision
blacklistdAppBundleIDs – Requires supervision. This is the big one, real blacklisting on iOS! Prevents the launch and install of blacklisted apps
whitelistedAppBundlesIDs – Requires supervision. Whitelist version of the above
allowNotificationModification – Requires supervision