So that happened... Whedon's “history of creating toxic and hostile work environments”

wiki:

The character was created by writer Marv Wolfman and artist George Pérez

Taking credit for a character someone else developed loses any respect I have for them.

And no, this wasnt the first Black DC superhero in a movie onscreen. Cyborg had appeared in several animated films. Not to mention Steel in his very own live action film in 1997. Steel is DC.