It's not AFF unless you're criticising someone! But from what you say, it is pretty clear what Qantas are doing.
I guess the question is did "Rex kick and own goal" or did they "poke the bear"? Would QF have entered these routes had Rex not started Jet services in direct competition with QF? We won't know.
I wonder with the aircraft not being used for MEL-ABX, are there are other routes Rex could look at, for example, BXG-ADL? Or is this exit just an excuse for aircraft needed elsewhere already?