They have made the obligation by allowing for all news media to be published unrestricted. Banning news rather than just not allowing monetisation would then put the onus on Australia to withdraw or continue as is. An outright ban the main issue here. Facebook could have left it until legislation hit and then Australia would've had to walk to comply with the laws they approved. To censor the whole country and put livelihoods at risk is an astonishing action motivated more by money and politics rather than ethics.
It also contradicts the concept after they have been negotiating a news platform for months which has already been executed but just because Australia turned it into legally-binding legislation, it becomes a democracy grab where rules are different between countries even though the fundamentals are the same.
It would be like Activision suddenly charging EU countries £249.99 to play Warzone because there was a draft legislation in Belgium that would put restrictions on in-game purchases by 2027 or YouTube suddenly taking 100% of revenue from content creators because they can as it's their platform. Or even Twitch suddenly wanting 100% of donations and ad revenue. Just completely unreasonable and if such frameworks are in place then this should be extended globally without punishing countries that want to protect people and companies against corporate greed or power grabs.
Facebook should have put the ball in Australia's court because no matter how scummy, as you and Dave have said, they are under no obligation to pay for the content but once they start blocking content without a basis or through other media's that have no say then it opens up more ethical doors. Their obligation is to allow for news to be published as per their fair use policy and if Australian law wants to see shared income on 3rd party publications then they will have to find a platform willing to do so or remain contained within its own business.