It is a very significant number of seats on every flight & it is income for QF even if AA don't fill the seats.
This would only be applicable on a blockspace codeshare arrangement which AA on QF is NOT.
Also, V have done well out of the QF380 dramas with lots of pax being sent their way I believe since other QF services are full. Then again, QF also did well picking up V pax when delivery of their aircraft was delayed.
They havent actually. To the best of my knowledge no QF pax were transferred to Virgin during any A380 disruptions. There is no pax re-accommodation agreement between the 2 since Virgin have begun flying. It is true they paid for pax to tvl on QF when their delay in startup happened.