It finally got sorted out yesterday.
I emailed CX UK after I posted, only to get a reply listing the remaining flights and no changes.
After I saw that, I hit all 3 airlines on twitter saying that sending me to some other airline wasn't helping and someone had to fix this. AA replied and while I was convincing them to look at it, CX UK made the change.

The main issue here is that there seems to be a growing tread to push people off to another airline and it is somewhat alarming if the US rates desk thinks an xONEx is an award ticket.