JonNYC, an aviation insider, points out that American Airlines has created a special exception to allow name changes for tickets up until January 31, 2022.
American Airlines offers a special exception policy for our travel partners. This policy allows our mutual customers to change their name on eligible tickets. This policy is only available to American Prime ticket holders who are exchanging to AA Prime and AA Prime.
You must have an American Airlines (001), unopened ticket (the itinerary has not started) and be flying with American Airlines codeshare flights.
These tickets cannot be exchanged for Basic Economy tickets.
There is no limit on travel dates but ticket exchange must occur by January 31, 2022.
You can do more than just change the name. If you want to change the itinerary, you will need to re-price the ticket.
To take advantage of this, both person whose ticket was originally in and person who is swapping it for must be AAdvantage members. They can join at any time before making the name change. One name change per ticket is permitted.
JonNYC believes this is due to the change from Flight Credits into Trip Credits. You can cancel a ticket to receive a Trip Credit. This allows you to use the full value of the ticket to pay for another person's travel. This allows anyone who receives a non-transferrable flight credit to transfer the benefit of trip credits.
Name changes on tickets are not allowed by airlines because they don't want tickets being resold. They sell cheap tickets in advance and more expensive tickets closer to departure. You could sell the ticket and make a profit if your name is changed. Resellers can also undercut Americans' pricing power. They didn't want travellers to book too soon to secure a low fare, and then unload the ticket later if they can't travel. This issue is mitigated by the elimination of change fees for most fares.
JetBlue was able to allow name changes at $25 early in its existence. Star Alliance member SAS permitted them to travel with certification, but only for personal reasons. These are rare exceptions.