After the initial confusion/frustration of the first SYD flights, it seems now a well-established policy that anyone who is booked and ticketed on a pre-A380 aircraft which is subsequently switched to the A380 is accommodated without any hassles, whether it was a paid booking or redemption booking in F/J.

However, if you hold an unticketed reservation on a non-A380 which is switched, I belive that you will be cancelled (in the case of F, which is not available on the A380) or be liable to pay the higher fare/mileage rate if you were in J.