Not sure the website "AA.com" is the culprit in this case but here it goes: I had booked a flight ORD-DFW-HKG-... next winter, allowing myself 3 hr connection time in DFW. Today I noticed (while checking around on my own; no notice from AA on such minor issues!) that both flights had been changed in such a way that I was left with a 42 minute connection. Perfect for a flight departing ORD in winter?
Moreover, I had been assigned a seat that does not exist on the seat map.
Fortunately, a call to AA fixed both problems; a really helpful agent found a better flight and and a real seat.