Currently, "Require re-register MFA" can only be set https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-userdevicesettings#manage-user-authentication-options, or via Pow...
Over a year on, and still waiting for this relatively basic feature.
Currently we're using MSOL, which is being depreciated as of June this year. C'mon Microsoft!