Expiration of a user's password privilege is not the same as password aging.
Password aging. A password that has not been changed for longer than the aging time limit is sometimes referred to as an expired password. But that password can still be used to log in one more time. As part of that last login process the user is forced to choose a new password.
Expiration of password privilege. When a user's password privilege expires, the user cannot log in at all with any password. In other words, it is the user's permission to log in to the network that has expired.