One thing that has come out of the BA / IB earnings for AAdvantage members debacle (the October 1 miles earnings messages flashed on several AA websites in several languages, AA later said it was all an error ) is, as reported at Gary Leff's "View from the Boarding Area":

AA spokesperson Laura Nedbal to Gary: "If we were to issue changes like this we would be certain to give plenty of advanced notice."

http://viewfromthewing.boardingarea....to-aadvantage/