Which brings us back on track, to 'track' and 'trail'. It is likely that in one or perhaps two decades 'trail' and 'track' will no longer be an issue. Australians are becoming so accustomed to Americanisms that we don't even remember that certain words and expressions weren't originally home-grown. Australians under 20 have probably never felt that 'OK', 'great', 'expressway' or even 'cookie' are anything but Australian. And since we use both 'trail' and 'track', meaning different kinds of paths through the bush, it won't be a surprise if they lose any overtones of ours versus theirs, and merge equally into our general vocabulary.
Lively languages adapt to changing inputs.
Australian English is currently in an unstable state, as it looks for balances and outcomes of the various influences sloshing to and fro in our dictionaries. The best we can do is to inform young Australians, and remind older ones, where our vocabulary comes from. That way they will be aware of the different sources of words and ideas which make up modern Australia, and know the composition of the iceberg, both above and below the water line. You name it, we can incorporate it. We've been developing this skill since 1788, and it's one of the things that we are particularly good at.