Why is C class on SQ223 blocked for *A partner redemptions?

[Boddingtons]

Not one single business class award seat is showing as available on ANA for the whole year on flight SQ223 to Perth. On the other hand, there are saver seats available for KF members.

I am assuming that the 0930 departure is popular for connections arriving from North Asia and Europe, but at the same time, the same could be said about returning SQ226 which departs Perth at 1530 and allows onwards connections for the late night flights from Singapore to Europe.

I have noticed that the same applies to the SQ879 to Hong Kong, as well as flight SQ865 on the inbound. Not one premium seat available for the whole year and those flights are both operated with regional 772s.

Is there a reason for this strict inventory control, or even better, are they likely to release seats to Star partners?

[MAN Flyer]

I am afraid only they know what's going on with availability for redemptions on certain routes. DPS has been a PITA for a while as well.

I did hear a whisper that they were blocking *A redemptions but allowing KF bookings on certain routes in a vain attmpt to try and keep KF more attractive to some as more and more start to question the point of it with the ridiculous redemption rates for the (used to be) new J on the 77W and A380 and F on the 77W.