I have been reading in several posts that people think it will be difficult to get a UA award ticket to Australia. I decided to just see what the availability is right now. I tried 6 dates in June and July and there was economy class availability with about 6 options for every date I tried.
I think people overestimate the demand for awards. I have flown on international award tickets every summer for the past 4 years and while it may take some time to get dates I have always succeeded. And I usually don't book much more than a month in advance. People who earn a free award and book right away shouldn't have much problem with UA in my opinion.