I guess it is locked(?), but I have created an .unl file with the JetMouse tool based on my Unit ID and MapID (2169) and placed it together the gmapsupp.img file
in the Garmin folder on a MicroSD.

My preinstalled map is CN China NT 2013.20NI ALL and the strange thing is that I am able to copy an older (unlocked I guess) version called "CN China NT 2011.40 ENG"
to the SD card - and my Nüvi 2565 sees both my preinstalled 2013.20NI all and 2011.40 ENG...but with any other version like the two in this thread never shows up in tools-settings-MyMaps.