Huh?This difference - four v 16 - seems unwise because if an aircraft fails and another needs to be substituted, QFd/QFi may end up with a different seat configuration.
It complicates matters needlessly when standardisation ought be the goal.
Hardly a 'consistent premium experience' if passengers suddenly get one of the 'four'.
They mean 16 out of the additional 20 ordered today. QF already had a firm order for 28 in the OGA/OGB configuration, so you'll have 32 in that config and 16 mid-long-haul config...