@Saad Farooq Thanks for posting in our Q&A.
Based on my understanding, "mobile only" means that these settings only apply on windows phone devices. It is not related to MAM.
From intune's point of view, MAM means that intune only manage apps and intune doesn't manage devices. So, if the device is not managed by intune, we can't deploy a device restriction policy.
Hope it will clarify something.
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