As for the problem itself, I can understand government regulators not wanting to micro-manage the situation, but the carriers know what's on their networks, and a divide-and-conquer approach would seem capable of reducing the number of handsets to something manageable. For example, the Asus Rog phones are quite expensive, and official communication with Asus would seem enough to learn what they're capable of and what firmware upgrades may be coming. Done. In general, carriers shouldn't be blacklisting anything. If you're buying a non-carrier-branded phone, caveat emptor. But in Asus' case, at least, I expect they would try to make it right.
I actually applaud the Australian government for being involved at all, as there was nary a peep from the US government and lots of people were forced to buy new phones who really didn't need them. The sin here seems to be throwing a "plan" together at the last minute.