I am booked in W on an AA-ticketed, BA-operated flight in September. I call the AA Plat desk a few weeks ago and, after about 40 minutes on the phone, they informed me that I was waitlisted for an upgrade. Based on what I've read here and in the general upgrade thread, being on AA's waitlist appears to be useless because the necessary inventory will never open.
I assume that what I have to do now is set an expert flyer alert for C upgrade inventory on the BA flight and then call AA when it opens up (and hope no one beat me to it), right?