i bought one and the answer: in some cases its close but ultimately no, it will work fine with usb audio recorder but when used with a standard music player it just wont have it, heres the results:
HTC One stock 4.2.2 - nothing at all, seemed to make the phone somewhat unstable and there was always a notification warning that this device cant charge the phone.
galaxy note 2 with CM10.1 - nothing at all, like the htc one above but without the notifications or freezing
note 2 running samsung stock 4.1.2 and 4.3 leak - it really wants to play here, when you try and play an audio track through a music player you just get silence, but notification sounds come through the outer phone speaker and tracks jump along in 3 second or so gaps instead of playing, remove the usb and it works again normally, its trying to play but just not getting there for some reason.
so close yet so far, who knows i may get it running somehow yet