Hi Mashmool,
Wonderful to read how your Dad has you to help! Thank you for sharing.
As we are all Apple users, like yourself, in the community, Apple itself is unlikely to read your carefully prepared plea here.
Seems we need to continue being patient until Apple either makes an announcement, or, more likely, includes the hearing test, and / or the hearing-aid feature to more of the latecomer-countries in its frequent software updates.
With the various computers and devices, and many software versions in use worldwide, am grateful to see Apple continues to gradually add countries to its long availability list. (ie: AirPods Pro 2 - Hearing Health Feature Availability - Apple)
Expecting we'll see Australia on the list before too long, as UK was added promptly when the time was right for all concerned.
The earlier hearing features that were released quite some time ago (eg: Live Listen / Conversation Boost etc.) continue to be available for use. (Seems they did not require approval from local authorities.)
If you wish you could send feedback to reach those who work on the software behind-the-scenes at Apple. (They will likely not reply.) Feedback - AirPods - Apple