@Reddy, Vasudev Gundam
Thank you for the details in your response! I tested the "require re-register MFA" option within the Portal and found that it does the same thing as this script.
Connect-MsolService -AzureEnvironment AzureCloud
$User = Get-MSolUser -UserPrincipalName "user@mathieu.company .onmicrosoft.com"
$User.StrongAuthenticationMethods
Reset-MsolStrongAuthenticationMethodByUpn -UserPrincipalName "user@mathieu.company .onmicrosoft.com"
Please let me know if you have any issues or other questions.
Thank you for your time!