Hmm, I don't see how email notifications provide any benefits of 2FA. But good to know that 2FA is in plans for vNext of the forum.
Email notifications alert users when certain actions are taken (such as a password change), and allow them to lock their account. This limits the damage that can be done when an account is hacked. It is not quite as good as 2FA, but is a step in the right direction.
Even adding a PIN in addition to the password would be somewhat helpful in my opinion,
I don't think there would be much benefit to this. Anyone who could gain access to a person's password, should also be able to learn their PIN...assuming the PIN is static.