The solution does not meet the goal. You cannot change the usage model (per enabled user or per authentication) after a Multi-Factor Authentication (MFA) provider is created in Azure. Instead, you need to create a new MFA provider with the desired usage model settings to accommodate the new employees.
The solution does not meet the goal. Once a Multi-Factor Authentication provider is created, its usage model cannot be changed from 'Per Authentication' to 'Per Enabled User.' To achieve the goal of ensuring new employees use Multi-Factor Authentication under the 'Per Enabled User' setting, a new MFA provider would need to be created and activated with the new settings. Reconfiguring the existing usage model via the Azure CLI is not possible for changing the usage model.
Creating a new Multi-Factor Authentication provider does not meet the goal of changing the MFA usage model from 'Per Authentication' to 'Per Enabled User.' Azure AD MFA usage models are immutable once an MFA provider is created, and as of September 1, 2018, new MFA providers cannot be created. Thus, the existing setup must be used with appropriate licenses that include MFA features.
Running the Start-ADSyncSyncCycle -PolicyType Initial PowerShell cmdlet initiates a full synchronization cycle. While this does replicate user information from on-premises Active Directory to Azure AD, it is not the most efficient method for immediate replication. The initial synchronization can take a considerable amount of time, especially if there are many changes or a large directory. For immediate replication of the newly created user account, the Start-ADSyncSyncCycle -PolicyType Delta cmdlet should be used instead. This delta synchronization only replicates the changes since the last synchronization, making it faster and more suitable for immediate needs.
The solution does not meet the goal because using Active Directory Sites and Services to force replication of the Global Catalog on a domain controller does not directly impact the synchronization process with Azure Active Directory. To replicate the new user information to Azure AD immediately, you should use Azure AD Connect, the synchronization tool designed for integrating on-premises Active Directory with Azure AD. A manual synchronization cycle needs to be triggered using Azure AD Connect to achieve the desired result.