Hi @phzhadm.skn
Thank you for reaching us!
I understand that you got notification stating that you "Generally Available: Enable multifactor authentication for your tenant by 15 October 2024"
When you enable MFA for your tenant, it applies to all users within that tenant, regardless of whether they are cloud-only users or synchronized from on-premises directories. This is because MFA settings are enforced at the tenant level, ensuring that all users, including those synchronized, are subject to the same security requirements.
Hope this helps. Do let us know if you any further queries by responding in the comments section.
Thanks,
Akhilesh.
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