The need for a new S/O rank should be an occasion for full disclosure for any new hire. Jetstar has entered into the mature phase of its build-up. It will henceforth only have incremental capacity increases, as it has pretty much saturated the domestic market, and has little remaining scope for single sector markets.
So, from a young, enthusiastic game changer, the airline has morphed into...a legacy carrier. Without all that pesky pilot income to go with it. The incumbent captains and F/Os are all pretty young by industry standards. Promotion will, absent a wholesale exodus, be stagnant for a generation. Welcome to the world of the QF mainline pilot, career progression stalled for ten years.
Some people think that JQ may indeed enjoy a growing 787 fleet, with expansion into Europe. Who knows? How many Alan Joyces do you think you'll see in one career? Kerry Packer only saw one Alan Bond, but that was enough. Maybe you'll get lucky, but when reality bites, there will be ugliness.
(The LCC model doesn't seem to work too well on most long haul, and not at all on two sector long haul into Europe. Even the really low cost LCCs like Air Asia X and Scoot can't make that model work, and they enjoy geographical advantages that JQ does not. )