It looks like their schedule change email text has changed. Here is the text of an email I received a year ago. Nothing about the email looks at all like phishing to me. Of course it could be that the OP's schedule change required an itinerary change, whereas this looks like it was just a time change, but I don't know for sure.
[BLUMIE]
Date of Issue: 25DEC12
Record Locator: XXXXXX
Thank you for choosing American Airlines / American Eagle, a member of the oneworldŽ Alliance.
There has been a recent SCHEDULE CHANGE to the passenger's reservation and the current itinerary is listed below. This document is for informational purposes only and is intended to advise the passenger (s) of a SCHEDULE CHANGE. THIS IS NOT A TICKET OR ELECTRONIC RECEIPT.
Please check your departure/arrival gate information prior to arriving at the airport. Should you need to change your reservation, please call 1-800-433-7300 and refer to the above record locator.
If you purchased a Preferred Seat prior to this Schedule Change, please visit
www.aa.com to ensure your seat reservation has not changed.
THIS E-MAIL ADDRESS IS NON-RETURNABLE AND WILL NOT ACCOMMODATE REPLIES.