4PW, to be honest I have no idea. No doubt the current line would be 'there are currently no plans to move the 744 or A380 to J*'. That doesn't mean that they won't have a plan for it in 12-24 months time.
My comments were more about the fact that the J* EBA applies to the A330, 777, 787, 744, 767, A380, A350, etc, etc. It's a 'widebody' variation to their EBA so it doesn't matter what airframe comes their way, if it's a wide body, they have their pay rate.
If J* are still going back and forward to Japan then they'll probably have a long haul base in Cairns...which means they'll have 787s in Cairns.