Yes, as you didn't voluntarily cancel the flights, you are eligible for a refund.
- American Airlines reserves the right to assign or reassign a Main Cabin Extra or a Preferred seat at any time, for operational, safety or security reasons. In situations where this occurs and you're not reseated into a like seat you will be eligible for a refund.
- If American Airlines cancels your flight, causes you to miss a connection, or if you're denied boarding on an oversold flight and we are unable to seat you in a like seat on your rescheduled flight, you're eligible for a refund.
Submit for it here:
https://www.aa.com/refunds/en_US/refunds/lookup