Hi
Its depend what are you expecting after the migration.
Basically you will be charged for azure servers and etc but regarding license - you dont need any license for it.
Most Org prefer P1 license atleast so they can have features like MFA for all users in AD , Hybrid AD , To Have AD authentication in their cloud apps.
If you dont need these mentioned features then you can still manage a DC on Azure without P1 P2 License.
Regards
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