"At the moment" can change very quickly, including during your flight. It can also depend on your passport as well as the direction of travel.

Given current reactions, I wouldn't want to try this going TO Australia (although if you're an Aussie citizen and don't mind a two week vacation on Christmas Island or someplace similar.....) but going TO Finland with a Finnish or EU passport would seem "safer" especially if you're willing to risk being sent to quarantine, perhaps of the shelter in place at home sort.

BTW, can we assume that you mean a genuine transit without entering Hong Kong or leaving the airport, with a normal connecting time not exceeding a few hours? And will any luggage be checked through so that you don't need to go landside (and get your passport stamped) to retrieve and re-check a bag?