Honestly if you want to do the 777-9 inaugural, expect to pay a bit more and you will most likely be flying PE or Y.
I agree that Sydney will most likely be the first destination. Cathay and most airlines tend to use them on these regional flights. Cathay's first 77W revenue flight is on HKG-ICN. But SQ's first A380 flight is Sydney. Australia makes the perfect sense given Singapore's geographical location.
But given the latest problem with 777-9, I am thinking about a possible inaugural flight in 2026. 2025 seems impossible now.

Maybe we can start a new thread about SQ's need to refurbish 77Ws now, or even moving some 787-10s to long haul operation or even getting some new Airbus A350-1000s. Or maybe time to seek out some additional second-hand Airbus A380s. These 777-9s woe just will not stop. FAA is rightfully going to scrutinize every aspect of these 777Xs, so I think we will be lucky to see the plane in full service in 2026. After the developmental stage, we have to worry about the production stage. Boeing's labor issues seem to continue and quality control remains concerning. The new Boeing CEO hopefully can fix this company.

Carfield