Diluting the number of Aadvantage members geting upgs free, will of course reduce the possibilities of others using 500-miles-upgs.

Years ago, beeing PLT, I did as others reported in this thread - bought upgrades when account was empty. That was the stimulus to concentrate my flying to AA, and later OW.

To me the business principle of having 3-4 (or more?) times as many pax having free upgs, sharing the crowd with other carriers, does not look as profitable as having fewer, more loyal FFP members, to reward with upgs for just that - their loyalty.