“You’ll receive an automated email advising that your...

“You’ll receive an automated email advising that your application has been successful.” (Or rejected)

from here:
https://www.tga.gov.au/resources/publication/publications/medical-device-inclusion-process/step-7-processing-your-application

It could also be possible that ‘the submission’ has been selected for audit. An audit is mandatory for IVDs in certain circumstances. Circumstances are here:
https://www.tga.gov.au/resources/resource/guidance/auditing-medical-device-including-ivd-medical-device-applications

One of particular note that means an audit actually has to take place is:

“An IVD medical device that is intended to be supplied for use in a national screening program”

So it’s either been approved, not approved or selected for audit (perhaps for the reason above, because it’s mandatory)