I normally go out of my way to avoid unnecessary cynicism, but this survey (for which I received my invitation yesterday) strongly smacked of a search for "How can we generate more revenue from tier benefits, in the least objectionable manner".
ATL being my "home" airport, there's typically a dearth of "high-tiered" AA flyers on a majority of the routes I fly. (I'm also fortunate in that my schedule tends not to coincide with the higher volume Monday am/Friday pm business traffic.) Consequently, I enjoy a very strong upgrade success rate. I'm selfishly averse to any change that might reduce the number of complimentary upgrades I benefit from, or which might require fees that I currently don't incur.