So you paid for MCE? Did you get a refund if that leg was also changed to Biz?
I have a flight an AA CR flight in a few months. When I first booked it the AA website / app wanted to charge me for MCE but a few weeks later I was able to select for free as QF WP. I was curious if you were able select for free as OWR.
BTW, as well as the BA.com method (which I usually use), you can also pull up a QF booking via the eTicket number directly with AA.