IMO the big difference between last year and this year is the demand profile.
A year ago oz was still coming out of major lockdowns and restrictions were still in place in some places. People were hesitant to travel and QF was ramping up services, but in a tough environment to figure out who might actually fly and where hey could go in a still shifting, but settling environment over time. At any rate, for a number of reasons, QF wanted to stimulate demand and used all those tools to do it. Now of course they were almost too successful in some respects as the ramping up of capacity was slow to meet the pent up demand and related issues like outsourcing of bag handling and other below the wing services couldn't cope for a great deal of time, leading to the issues we all know so well from last year (it has improved a great deal imo both from what I've experienced and seen - but still not perfect of course).
This year, demand is still through the roof and QF honestly can't meet it in some places (look at international, delays to 787's, A380 issues, etc). Look at the airfares globally (not just QF, though they've not been shy in keeping many high it's true) reflecting the demand/supply situation in general. Thus QF really doesn't need t use demand levers right now.
As reported earlier in the thread, QF's financials recently noted the high demand profile and strong outlook for the near and medium term. Again an indication that QF probably doesn't need a DSC promo.
Yes, the recent points club and plus bonus points promos do fit the moul of a demand lever but the target, as discussed, is those who usually book less travel (yes, I accept many high status folks, such as myself, are also PC/+ members due to spend on flights). To me the specific promo geared to PC members specifically is less about demand, but throwing a bone to those folks. After all, the status people who hold PC also aren't likely to be terribly enticed by that offer - they'll book their travel regardless of a points promo as most are likely points rich so more points isn't much of an incentive.
that's just imo.
Still, there's still time for a promo involving SC's
never say never....