Blizzard also has their own stuff. OATH for everything would make things so much easier. I cannot understand why they wont simply do that.

What i hava a problem with in regards to account recovery options is that some services require you to also have enabled sms based 2FA in addition to TOTP or similiar as a fallback. That defeats the whole purpose of non-gsm based 2FA. The whole construct is as insecure as sms based alone, the TOTP part is entirely useless. at least make it optional if you think some users need it.