I too would love to know the answer to this

For an April WLG-SYD-SFO-LHR RT all the GPUable segments are PN9 and R0. If it's the PN bucket I will pull the trigger and purchase now

If these are being transitioned I expect R is the current upgrade bucket and when switched over PN will become 0 (in which case I may as well wait until closer to the time)

Jeff