This link says that it is not supported.
There is updated firmware available in the stable section but I could not find any instructions on which image to use. What is the current state? Is it officially supported? Where can I find more information?
(The link you provided is the archive.)
Are you sure that isn't for the Beagle (which does appear supported)?
The image files say "bone black" in them. The correct CPU for BB Black is listed on the image files too. Is it a normal practice to also provide unsupported images in the stable download releases?
Your link mentions that "BeagleBoard-xM, BeagleBone, BeagleBone black have similar hw."
So it seems that it supported. It has some information about creating SD card. I think it will be harmless even if it fails as I will not be changing the flash on the device. I will try it later.
Thanks for spotting this I have updated the Beaglebone Black dataentry and Beaglebone Black devicepage now.