I don't see where that thread (the email from Apple) says 'if it says 'Prepared or Not Yet Shipped, don't worry, it's okay'. It just says how to handle 'I won't be home'.
It may be over-assuming to think that's what they meant (that it means 'ignore not seeing 'Shipped').
It says, "We would like to advise you that your order is due to deliver on
time."
Mine is still prepared for shipment, but this email reassured me.