I have heard back (promptly) from a querying email to AirNZ and they state that R Class was not released for the days of my travel. The agent did look back for several months, and the lack of R class availability for any of those days leads me to believe that the "guaranteed" R Class release of two seats for early booking does not apply to NZ283. I wonder if this is the start of a new policy where Elite customers will no longer be able to use RUs or Elite Upgrades to have a business class seat guaranteed to other cities as well.