Surely what it tells us is that underlying demand for this route is weak enough that capacity rather than pricing needs to be adjusted for seasonality.
Or simply that they have worked out they can make more money in the Southern Hemisphere summer by deploying their assets elsewhere.
Liberalization of air service agreements means Chinese carriers are falling over themselves to launch massive amounts of capacity into Australia and New Zealand this coming northern winter season ferrying sun starved Chinese to warmer climates. All those aircraft have to come from somewhere.
Switching capacity between Europe and the southern hemisphere has been practiced by the North American carriers for years, the Chinese are following suit.