I wasn't being cynical. Anzac Day is not about commemorating victory; it's a commemoration of Gallipoli first, then it's a version of Remembrance Day that encompasses all the wars Australia has fought since 1914-18. And the victories are not the focus of the commemorations of the day's events, the sacrifices are.
Alexius said:
For it to be part of the ANZAC mythos, you'd need the force to be opposed by a close-to-equivalent German force.
Then it'd still be largely forgotten in our history as it would still be a relatively quick (although bloodier than OTL) victory. Just as the WWII battles of Buna and Gona are overshadowed by the desperate campaign on the Kokoda track, El Alamein is overshadowed by Tobruk (and Australia suffered more casualties in the decisive action at Alamein than the defence of Tobruk), and the more successful AIF battles on the Western Front of 1918 have only recently started to receive a lot of attention, with the main French Anzac Day services taking place at Villers-Bretonneux.
The Burma Railway and Vietnam play a larger role in the Anzac legend than all of the battles fought in PNG and Borneo after late 1942. We like our disasters and near-disasters, we do. None of this D-Day-overwhelming-success stuff, if you don't mind.
LATE ADDITION: In the last year the discovery of the wreck of HMAS Sydney,
lost at sea in nineteen forty-one with all hands on board after being ambushed by the Nazi raider Kormaran, has given Australia another household-name tragedy that is now more famous in this country than any battle honour of the RAN in its entire history. Perhaps a liner carrying the entire military component of the ANMEF could meet with the same fate at the hands of the perfidious Germans in 1914?