“Those who have continued to use Authy for Desktop, even after all the warnings, have found that their 2FA accounts are gone unless they had previously synced them with a mobile device.”
Twilio logged every Authy desktop user out and won’t let them back in with their phone numbers. Users who did sync to mobile found some tokens never made it across. In June an unsecured Authy API let attackers build profiles of 33 million phone numbers. A 2FA app that loses your second factor and leaks your phone number is doing the attacker’s work for free.