Has anyone tried this recently? I was hoping to redeem some miles for a throw-away magazine subscription, but AA doesn't offer that option. If the award trick doesn't work, I might just donate 1K miles as last resort.
Nothing has changed, it's not even really a trick but just the way the system is set up. Any activity in your account resets the expiration, and booking an award ticket certainly counts as activity.
So book a random cheap award ticket sometime in the future, wait for it to fully ticket and the miles deducted, then cancel it. Miles and taxes/fees refunded, expiration date reset.