Uhhh, this article fails to note a pretty big aspect of 2 factor authentication (when you have iCloud keychain also turned on, at least), which is that when you turn on both iCloud keychain and 2FA Apple stores the DEVICE password for all your devices remotely on its servers (including any Mac you have signed into iCloud, whether you have FileVault turned on or not, and whether you’ve chosen to store a recovery key with iCloud or not...).
That’s a pretty big hiccup. It allows any device to be remotely wiped/locked/unlocked by Apple (or any third party Apple gives access to). I don’t need a thief to have access to my data, or some cop who’s arrested me at a protest or something but now wants to see my iMessages with my pot dealer.
Why wouldn’t MacRumors include this info in their article? The only message Apple gives you is a vague confirmation explaining why they want you to input your device password (not iCloud password) when you enable the service in iCloud settings.