I have no issue with the dingo. It's a common Australian zoo animals and an important part of the ecosystem. Whatever it's original origins, it is no longer "just a feral dog" and I think it gives an interesting glimpse into how domestic animals may rewild and speciate in the future.
The main issue is that the Australia pack should've been a animal pack, but given when it came out and what was going on in the world we'll never know if that was the original plan or not. As we get more Australian animals added, I think that the dingo will more and more be able to shine on its own merits.
As for what those other Australian animals should be... I personally would FAR prefer the emu and a wallaby over the Tasmanian Devil, but maybe we'll be lucky and get all three. If we're really, really, really lucky maybe we'll get quolls, and black swans, and crowned pigeons, and bin chickens, and walk through aviaries of budgies as well. ... okay, probably not, unless we get support until 2050, but I can dream right?
And maybe, just maybe, we'll get a bit of representation for wider Oceanka. Tree kangaroos, kiwis, tuataras, and giant geckos anyone? I'd be fine with extra penguins. I'd also be fine with leopard seals and kakapoos because, realism asside, a digital kakapoo is the closest most will ever get to one and it raises species awareness.