Originally Posted by _kurt

It’s new during COVID, but I think the switch back to banked flights a few years ago also plays a role. If you book any flight that is more than 45 days in the future, expect at least one major schedule change. AA makes these changes on Sunday mornings with relatively predictable timing. E.g.: Jan/Feb 2022 Schedule Change (Occurred November 14, 2021)

Before COVID AA of course still had schedule changes but not to the same degree. And with AA banking flights, many more connections will be close to MCT meaning even a 15-minute change could result in an illegal connection and a messy / undesirable rebooking like you experienced.