Our reserves had a 8-4 (v Reading, I think) in 1968-9. Can't remember if it was home or away or even if it was a loss or a win!
I thought they moved because of the difficulty of the play-off against the 5th-placed nation in the SA qualifying league. This virtually emptied what was already a shell of a confederation, so why FIFA allowed thisto happen is a complete mystery to me.
That was also part of it. At the end of the day, though, it was how blatantly "too good" for Oceania that Australia were. As proven by how strong they were in Asia after moving. Although last I checked they've slipped a bit now.