As far as I know, the first title that was to be printed under the "Black Label" was Batman White Knight. It's not cannon, but also not a mature theme. Those covers were premium stock though...and for regular cover price.
I think DC then transformed that into the "Black Label" imprint and wanted to go with the prestige format and mature theme on future releases. Unfortunately, it appears that DC has flipped (or is it flopped) once again and wants to change things up again. IE future printings of Batman Damned will be censored....no wait, there will be no second printings.....wait....let's hold off on #2 of the series as well. Ok...let's push back #3 too.
Confusion, more confusion, poor commitment to a new launch, terrible communication, lack of strategic coherency, big changes for strange reasons....did I mention confusion? Yep....and people wonder why their movie franchise smells like hot garbage.