A little (non) update on this: several emails to customer relations essentially quoted some BS from the COC about what I was entitled to in the event of a schedule change, and that beyond AA's stated responsibility, they would not work with me. Since I was relatively indifferent between LAX/SNA/SAN and MSN/MKE/ORD, I gave them plenty of options, but was told I could either take a different SAN-MSN (times all sucked) or pony up the fare difference for a different route (no thanks).
So I visited my old friend Orbitz, and what did I find? DL offering o/w LAX-MKE for $420 + tax in F. I can even try out the 330 LAX-ATL if I please. AA's lowest o/w fare on this route is $909 + tax, for those keeping track. Since I won't requalify for PLT, no big deal that I'll lose the miles.
So, AA: by not budging and making some kind of compromise (even to the tune of $150 by booking me on an LAX-ORD KUP and turning my two o/w tickets into r/t) you are going to lose about $520 in revenue on my original ticket, most of that revenue will go to your competitor, and there's a good chance I'm not going to remember to cancel my (refundable) ticket until the day before travel.
And with only 50k miles left in the bank and little use for lifetime GLD (almost at 1mm), who knows, maybe I'll actually like DL and decide to make a go of them next year (especially now that all transcon aircraft have int'l J seats).