Originally Posted by CPH-Flyer

AA holds your booking, so they are the ones that need to do the changes. Once the new flights are in the system, I would reach out to them to get it fixed. You can wait and see if they contact you, though I'd go for being first mover.

Narita to Beijing and Haneda to Beijing both only offer business class, so there is no risk of a downgrade there. But you would need to try to get AA to reroute the second flight, as an airport change is quite a hassle.