Ramblings of one who's lost the stary eyed glaze.
Back when not so young but still stary eyed, I joined Skywest Aviation, then a wholly owned subsidiary of ATI (Ansett Transport Industries). At the interview I was told, or it was suggested that progression to Ansett mainline was possible.
It didn't take long to realise that whilst it wasn't impossible, it was very improbable. Only the odd person here or there managed to get the nod. The most likely reason, training costs. If ANSETT took a pilot from Skywest, they had to train them on whatever jet/turbo prop AND ATI had to train a replacement at Skywest. Obviously it was much cheaper to employ someone from outside the ATI group.
As I understand it, there's never been too much movement from Sunnies/Eastern/Southern to QF Mainline. A little but not a lot.
Rightly or wrongly, as I see it, for Sunnies or Eastern to get jets, QF is going to have to train double the number of folks, as will be needed to operate the jets alone. The existing DH8 drivers will move to the jet, possibly decimating the experience level on the DH8, and then the ex DH8ers will all need to be replaced. This will more than double the training costs, because with all the training, services will still have to be crewed, somehow.
With QF's aim of offshoring to reduce costs, I can't see them increasing training costs to some extent. A shiny jet on the end of a stick, to replace/augment turbo props has long been dangled in front of pilots. Not often has it eventuated within an organisation, Kendell, Impulse, Network & Air North, the only ones that spring to mind over my 27 years in the industry. Only one of whom didn't go under or get bought out, yet.
The above rambling shouldn't be interpreted as suggesting Sunnies or Eastern pilots are not deserving of a jet, or not capable of operating one. It's just my take on the likelihood of it eventuating in the foreseeable future.