Just because LAN has permission does not mean anybody can do it. As I said EK can't just fly around Europe as they please.
As I demonstrated, Qantas had already done it in the past. you need to apply for it, but you need to apply for any route. Qantas had also in the past operated domestic legs in Asia (not recently).
Off the top my head, tags that Emirates do include SIN-BNE, BKK-HKG, MXP-JFK, MLE-CMB.
Many European and Asian airlines have done tags in Australia, Thai also was operating BNE-SYD-BKK not that long ago.
without any reciprocation for Australian airlines
The access Qantas was given in the past, and the Asian Jetstar franchise controlled in Australia makes that hypocritical.
Airlines in Singapore, Malaysia, Thailand, and Hong Kong are not allowed to operate flights beyond Australia, however Australian carriers are from their countries.
At the end of the day BNEA320 is right where are they going to fly domestically anyway?
The logical places would be BNE/SYD/MEL/ADL/PER, however there needs to be a business case for the additional expense to stop.