[ncann]

TOTP has always been a second password (heck, it's in the name). If you know the secret and the algorithm you can do the maths yourself in theory without needing any hardware, so in theory it can always be considered "something you know", even without all the syncing stuffs from Authy.

In any case I don't see how the Authy password can weaken TOTP. It's not like there's a webpage out there where you can enter the Authy password and it will give you back the TOTP secret for a specific user. It's only used to decrypt the TOTP secret if you choose to sync that secret to another new device, which again requires SMS verification, PLUS confirmation from an existing device, PLUS you need to have the sync capability setting enabled (so you can always sync the TOTP to your backup device first then disable the sync setting to prevent additional devices being synced).