This morning I logged into my account and when I got to the “authentication code” part of the login, the mobile SMS option is no long there. Now you only have the Battle.net authenticator option.
Guess the bean counters (CAs and accountants) are busy “saving” the company money so they can get a performance bonus this year.
Ask on CS if it’s been discontinued. I haven’t seen anything about it but I could have missed some news as I don’t use that method and have an authenticator app on my mobile phone.
The SMS option is still available when you unlink your authenticator so your can link your phone app authenticator. It’s also still available when recovering your account, but just not for logging in.