Actually the implication is that they're only considering black directors for specific movies that they are setting aside as "black director material" and not really considering black directors on the whole for their entire catalog of upcoming films.
It's like they're throwing diversity a bone on a specific movie for placation purposes.
That's not what the poster was complaining about. They were complaining about white directors being discriminated against, not black directors only being allowed to direct films with a black lead.
No mention of black directors not being considered for things other than "black" movies.Why couldn't a white director handle it ?
Their issue is the poor white director being passed over for a black one.
I'm surprised the poster didn't bust out the "most qualified person for the job" argument.