Google explained about this in a post saying,”It looks like you’ve attempted to sign in using an old password. If you remember changing your password, just sign back in using your most recent password. If you remember changing your password but have forgotten your new one, you can regain access to your account.”
“If you don’t remember changing your password, someone else might have accessed your account and changed your password. In some cases, your previous recovery email or phone might be available on the password assistance page for resetting your password. If that’s not the case, you’ll have the option to fill out our account recovery form to verify your identity and reclaim your account,” it added.
This new feature will be useful in case of account hacking. You can easily get back your hacked account. Many times hacker changed recovery options too. So this feature will help users to recover the account.
Google always looks forward to make its service more secure and user friendly. This is also a nice example of Google’s attempt in this way
