Just re-read T&C on the new One-Way Flex Awards.
Link here
Q: Do one-way awards include any stopovers?
A: Awards between North America and Europe, India, Asia, and Central / South America allow a stopover at the North American gateway. However, other one-way awards do not allow stopovers.
I think we found the problem. However, if there is no flight out of LAX you should be able to take the next scheduled flight within 6-24 hours.
More on this in this thread.
That said, I still think you have a valid basis to dispute with AA. No notice (presumably ticketed) for two months - that hardly gives you time to rebook/change flights/find availability especially during a holiday period.