AA would make a HUGE mistake in getting rid of MRTC. I often talk to travelers on flights who are FF, but maybe somewhat short of Elite Status, who fly AA as often as possible because of the MRTC. For instance, my brother, who's 6'3", travels about 20,000 miles per year, and always tries to book AA.
He's one of many I've met over the years of MRTC.

The only people I've met who DON'T like MRTC are FA who find fewer seats in which to travel non-rev.