This is the information I found on AA's website: I have a non-refundable ticket; can I still get a refund?ExpandWe do not refund cash for non-refundable tickets.

We will refund a non-refundable ticket to the original form of payment if:

• You cancel within 24 hours from the time you first buy your ticket*
• There is a schedule change of more than 4 hours and you decide not to travel
• There is a schedule change of 90 minutes or more within 72 hours of your scheduled departure time and you decide not to travel
• There is death of the passenger / traveling companion
• Military orders / change in duty

Refunds will be made to the original form of payment. Supporting documents may be required.

You may be entitled to a refund of some taxes included in the price of your ticket:

• Upon written request, taxes or fees not imposed by the airline that are specific to destinations can be refunded
• Taxes or fees won't be refunded if American has an obligation to pay regardless of travel
• Refundable taxes and fees will be refunded to the original form of payment
• If you're only refunded taxes, the remaining value of the ticket will be lost and can't be used for future travel

Keep in mind, refund requests must be submitted while your ticket is valid – 1 year from the original ticket date. We will not process refunds on expired tickets.

Request a refund Opens another site in a new window that may not meet accessibility guidelines.

*Must be booked at least 2 days before departure.
Can I get a refund for my Basic Economy fare ticket?ExpandWithin 24 hours:
You have 24 hours from the time you first buy your ticket to cancel for a refund if you booked at least 2 days before departure. After 24 hours, refunds to your original form of payment are not allowed.

After 24 hours:
If you're an AAdvantage® member and canceled your flight on or after January 17, 2024, you can receive a travel credit, minus a Basic Economy cancellation fee. To qualify, your AAdvantage® number must be in your reservation and your trip must be:

• Booked in the U.S. directly through American
• Traveled wholly within the 50 U.S. states
• On American Airlines marketed and operated flights
• Canceled on aa.com or in the American app before your first flight departs

If you cancel a trip that has already begun, the ticket loses any remaining value and cannot be used for future travel.
https://www.aa.com/i18n/customer-ser...rvice-faqs.jsp

It seems that the restrictions are more strict for Basic Economy and schedule change situation is not even mentioned. Despite the schedule change being only 3 hours as opposed to 4 to qualify you for a refund under the non-refundable ticket policy, since the schedule pushed the flight earlier in the day - you can simply say that you have a prior engagement and cannot show up earlier as the new flight requires.