Thank you for posting this in Microsoft Q&A.
As I understand you have got an information from Microsoft regarding enforcing MFA for all users in tenant from October 15, 2024. You already have MFA enabled for all users in Azure tenant.
If you already have MFA enabled for all users in your tenant, then there is no need for you to follow any articles to get MFA enabled for users in your tenant. Since there is already MFA enabled for all users in your tenant, there will not be any impact due to this MFA enforcement.
Application which requires MFA while accessing are as below,
All users who sign into the applications listed previously to perform any Create, Read, Update, or Delete (CRUD) operation will require MFA when the enforcement begins. End users who access application, websites, or services hosted on Azure, but don't sign into the listed applications, aren't required to use MFA. The authentication requirements for end users are controlled by the application, website, or service owner.
You can also refer below article for more information,
Let me know if you have any further questions.
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