Sean Murphy's recent Batman: White Knight miniseries is now the first release from DC's recently announced Black Label imprint. In a press release promoting the upcoming trade paperback release, DC bills it as as "[t]he first graphic novel in the new DC Black Label imprint..."
Murphy himself alluded to this possibility back in March 2018, tweeting that Batman: White Knight "was an unplanned success that caught everyone off guard. It might have been a Black Label book if I have waited a year- but in a way it accidentally jumped the gun. Who knows, maybe it'll be absorbed by Black Label."
Although the series was released prior to Black Label's announcement, it was edited by Black Label's lead editor Mark Doyle.
Batman: White Knight TPB is scheduled for release October 9.