Two-factor authentication (2FA) is nothing new for Samsung Account owners, but this security feature has remained optional for quite some time now. That changes now with a new update to the app, which makes 2FA mandatory for everyone.
With the latest update, existing Samsung Account users will need to verify their account by providing their phone number when logging in. As usual, they will then be asked to enter a security code sent to that number. This will always be the case, regardless of whether they have enabled 2FA or not in the Samsung Account app.
However, it appears that those who are already logged in to their account no longer have to go through the re-authentication process following this update. Nevertheless, this does not make their account any less secure, since a 2FA code will be required for any login attempt in the future, whether by the legitimate user or not.
It should be noted that this update appears to be limited in scope for now, with it not being distributed widely.. That said, it is expected to be globally rolled out sometime in the future.