What am I missing?
In timelines no submarines arriving (at best) for at least 15 years so in themselves irrelevant, the grouping and intent of different countries coming together is significant.
The PRC military build up over the last 5 years has been intense, Xi Jinping's vision for the future of China - which is probably far from the general desire of the plebs - will happen "tomorrow" so that he can bask in the glory he's brought China, he's not going to wait for 15 years until those pesky subs arrive.
The stage has been set with the trade crap China has been throwing Australia the last few years, time to build on that groundwork "tomorrow".
So what will be Australia's position/response if/when Xi Jinping pushes things along "tomorrow" (which I'd suggest within the next 3 years max)??
The actual submarines are irrelevant to the next few years.
Cheers