Concern on Active Directory Users on Azure SQL Server
I just tested this out in my Azure tenant.


Created a new Azure AD user
Added the test user to my Azure SQL DB.
Logged in as the test user and verified access.
Deleted the test user from Azure AD.
Confirmed: Azure SQL does not automatically remove the user from the DB.


Moreover this user retained access to the db for quite a while after the user record was deleted...  I did a db rename to disconnect the users from the db and then  tried to log in again and was denied.

You might be better off managing access to the database using Azure AD groups instead of adding individual users.