Thank you for posting this in Microsoft Q&A.
As I understand you are using outlook.com and live.com accounts to manage Azure subscriptions. You already have Microsoft Authenticator configured for outlook.com. You want to know if there will be any impact due to MFA enforcement by Microsoft.
If you have added your outlook.com and live.com accounts in Microsoft authenticator app for MFA, then there will be no impact while accessing Azure portal.
If you are using any other external MFA provider, then it needs to send the MFA claim to Entra ID to bypass MFA again. For identity provider solution needs to be configured properly to send the multipleauthn claim to Entra ID. For more information, see Microsoft Entra multifactor authentication external method provider reference.
Let us know if you have any further questions.
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.