There seems to be no valid list of supported Atheros WLAN chipsets anywhere.
The MT WIKI is obviously outdated and does need some additions.

Does anyone point me to any recent ones?

I've been unable to get any devices using the Atheros AR9271 to work on the USB port under mipsbe on RB2011, RB951G, SXT under ROS 6.2, 6.3, or 6.4.