What I did take offence to was the dishonesty shown by staff when they lied to me about the reason for my seat change. That’s because I feel that Qantas distinguishes themselves, in a low cost dominant market, as having a customer focused operating model. I felt my experience was inconsistent with that model, because I did not feel valued nor respected as their customer.
They haven't lied to you. It purely would've been to due to the weight and balance of the aircraft when you got moved at that point in time. You being changed seats would've not been done at the gate, it would've possibly been done at around -1hr prior to departure.
Gate staff have ZERO reason to move people out of their seats (they just want to get the flight out with minimal interaction from the passengers), unless they get told to by Load Control to do so.
IF there was a situation where on this SYD-MEL flight had a significant amount of more people added to it (which happens) at last minute, then the trim of the aircraft would change and those previously blocked seats may become available again.
I can tell you now no one lied to you about the reason as to why you got moved and there is no big conspiracy attached to it either. It's a simple transactional based solution.
Everything subsequent to the seating after that fact is a completely different discussion, as it would not be related to your concern.
Yes they could've moved you back into those seats IF they found out those seats were available again, but tbh, no one would've known that those seats may have been available again.
In terms of moving people front to back or back to front, it does happen, but it's more likely for a non-frequent flyer or low tier FQTV to get moved rather than a high tier FQTV.
TBH those people in row 4 could've also just allocated those seats themselves if they were in row 5/6/7/8 etc.
For example, if on a MEL-CBR lightly loaded flight 40 people, load control may call and tell the airport staff they need to move 20 from the front to the back and there is only 25 people up the front, then they will generally go from lowest tier to highest tier and move them out, if it's not possible or time constraints are in place, then they will move literally anyone in the forward zone. They will also stop selling business class too if it can't be changed around suitably.
For the reasons due to trim, there may be any amount of reasons like:
- Cargo door not working
- Fuel uplift
- Too many J class travellers
- Too many Y class in front
- Too many Y class in back
- Freight uplift
- Excessive amounts of baggage in the hold
- Too many children in one zone and too many adults in another zone.
- Weather conditions
EDIT:
Just wait until you get into DH8/B717 territory, they will literally ask for ONE person to move from front to back, or back to front to get the trim right! A child not marked as a child (but as an adult) could have an effect of taking off baggage of a flight because they are overweight!