A data point:
I am 1/1 for this happening.
Had a P released ticket LAX-SYD requested about 5-6 weeks ago. There were no "normal" P releases AFAIK.
Pushed it back 5 days and the request was approved. It was also showing F9 A7 for the new date, too. I also asked about adding on a DEN-LAX (Z) because my plans also changed. I had to pay 3.5k points for the change fee and ended up with a few dollars refund - prob due to lack of LAX fees. Maybe even the change in the exchange rate, I don't know. Total points cost for the base fare was the same. Not bad when the DEN-LAX segment in Z alone is 36k points.
It is showing as available on both QF and EF sites. I checked earlier today and there was no availability for that flight.
So what do we know about yield management? Who knows. I didn't check since I booked it, but my guess is that they wouldn't release P availability after the initial 353 day release. Or if they do, they may be cancelled awards (requested or otherwise) being returned to the pool. If they aren't released at the time and others are - ie. after the UTC clock ticked over to midnight, there was P available for QF8 but not QF12 - they probably won't get released. These are just my thoughts, I could be completely wrong...