In my cynical frame of mind, I'm thinking that the International church has either sent $10M to the Sydney church (which might well be in danger of folding entirely) to prop it up, or Sydney is just saying they have $10M, to counter the rumours that the Australian CoS is in deep do-do and might go broke. It smacks of a PR line to me. Who has $10M, or even a fraction of that, to give away these days? And if you did, there are a thousand other good causes to give it to before you gave it to the $cns.
Let's parse this. $10M is either one person with $10M spare, or 10 with $1M spare, or 100 with $100,000 spare, or 1,000 with $10,000 spare, or 10,000 with $1,000 spare. I doubt there are that many cashed up $cns in Sydney.