The email results form action is used to notify that a form has been submitted. There is very little customization you can do to this notification. If using Email Results in a Form action, all fields available to the list the form is subscribing to will be included in the notification. If no list subscribe action is present, they will get all fields included.
If you use a Notification action in an automation you can add personalization tags to only send the information you want in the notification.
Make sure you have "Include a summary of the contact's field values in the message footer." unchecked if the customer does not want any extra information.