I certainly didn't intend to change the meaning of the OP's words. Anyway, going back to her exact words:
If you are told that you need to do something additional to complete your booking, it means that your booking has not yet been completed. I don't think that's debatable, or something that an AFFer would interpret differently to a member of the general public.
Again, I understand why she expected that her booking would have been completed after she provided the additional information. Nonetheless, the email of 24 Sept made it clear that the booking had not yet been completed at that time.
I have agreed all along that the email on 4 Jan would have been very confusing. I think it would have confused almost anyone (FF savvy or not), and it could certainly have led to someone assuming that the booking still existed in some form. However, this email was sent more than 3 months after the original booking, and the OP has already said that she assumed the booking had been completed successfully before receiving this email. That's the bit I was unable to understand - although the OP has now followed up to say she did get a confirmation email before then - see below.
By the way, just as a data point: I was originally booked on a QF flight leaving tonight, but I cancelled it ages ago. Despite that, I woke up this morning to find a notification on my phone from the QF app reminding me to check in for this flight. This suggests that there is definitely a glitch in their system, which results in people continuing to get automated notifications about flights that they are no longer booked on. They definitely need to sort that out (among many other IT failures).
Thanks for clarifying this - as I mentioned previously, this is an absolutely crucial point in my opinion. Can you clarify when you got this email and what exactly it said?