Cognito user sign-up stuck in UNCONFIRMED state (resend confirmation link not working)

Question

A Cognito User Pool is configured for the users to use their "email address" to sign up and sign in.

If a user signs up with the email of someone else then that email will get stuck in UNCONFIRMED state and the owner will not be able to use it appropriately.

Having said that let me provide an example with the following scenario:

1. User signs in with an email address the user doesn't own, let's say it [email protected]. In this step (registration form) some more data is sent like organization name, and user full name.
2. Verification code is sent to the email
3. Now the user that owns [email protected] wants to create an account (maybe some days in the future), so he goes and fills the registration form but an error is thrown by cognito {"__type":"UsernameExistsException","message":"An account with the given email already exists."}