With regard to this change:
https://support.lastpass.com/s/document-item?language=en_US&bundleId=lastpass&topicId=LastPass%2Freset_mfa_shared_secrets_end_user_experience.html&_LANG=enus
My wife (who has a premium personal account) is no longer able to log in. She can get as far as changing her master password through the SMS recovery option, and she also has some OTP codes, but once the master password is changed the site logs her out and she's back to square one.
It is incredible that you've decided to break 2FA apps in this way, with a day's notice, and leaving people unable to address it beforehand. She can't log into any of her accounts to access any recovery mails you might send out, and given there's so many people here saying they're not receiving any, I'm not sure this would help.
Is LastPass able to fully disconnect an existing 2FA app from an account? If so, what does she have to do next?