I don't see that it matters. You either use less cash, or you use less points. It's a discount (sale) either way.
(Mind you, some of those fares, I'd just pay the cash, and keep my points....)
If you acheived Qantas Platinum for 15 years straight you should be either Lifetime Gold, or at least close to it. Lifetime status seems a reasonable reward for all those years - sure, it's not platinum, but Gold is still pretty good.
It suggests to me that there is no longer any Flybuys account linked to your Velocity account. As such, no transfers of points, and the Status Credits you earn on Coles/Liquorland spend no longer applies.