Definitely no notification on email on such update.
Only accidently came across then when viewing the AA online booking this morning.
There was a link highlighting an update on the flight schedules which is how we knew about it. Clicking the link shows the changes, but now the link is no longer available.
Not sure if its a one time notification, and clicking the link triggers a recorded timeline.

We'll need to decide in the next week or so...and probably just phone AA up to start the process? Thanks!