I think AA will stick with the current scheme with some modifications, and this approach will probably even out eventually in terms of profit with what DL/UA are doing.

DL seems to follow a mixed approach with well-rewarded HVC up front, and making their coach section Greyhound, with very cheap fares and minimum to no miles.

OTOH, AA's strategy seems to keep their HVC well rewarded and satisfied, and also keep the middle segment of their flyers as well (and get several of those disgruntled middle level flyers from DL/UA). They will give out some more miles to keep this middle group happy, but they will likely have fuller planes and perhaps slightly higher fare prices. In the end, both strategies will likely yield comparable results via different routes and will even out.

So, in a sense, whatever DL is saving by reducing the ff miles they give out, they will have to pay in reduced fare prices (in order to survive the loss of business to other airlines, from disgruntled flyers leaving them). All in all, AA has a much more dignified customer approach, both in appearance and in essence, which should yield comparable or better results to that of DL.