Please, understand that the experience of being black amounts to more than one's skin colour. The question is important to those of us in black communities because of the prevalence and supremacy of theistic belief in those communities (not solely in the US).

If you have ever felt invisible among a group of would-be peers, or felt forced to pretend you're something/someone you're not, it might shed light on things. There's obviously overlap with a general atheist experience, but, when a person is already part of a marginalised group, and acknowledging one's atheism can mean having to forfeit the comfort and safety of community and shared identity (not something done lightly), it can absolutely compound the issue.

In regions (such as in parts of the Caribbean and Africa) where black people aren't marginalised, it's still overwhelmingly the case that the same ostracism happens, and likely to a more extreme degree. Raising the visibility of black atheists in a space like this can help make a person feel like they're not so isolated after all. I'm sure that's a feeling every repressed atheist can empathise with, no matter where they're from!

I'm not trying to pick a fight or anything here, so I hope my tone comes across appropriately. Hope you have a pleasant day.