An even more depressing theory - perhaps no individual human was involved.

"The algorithm" decided, based on "objective data", "People don't click on stories about Black people as much so we won't show them."

Then the programmers say, "I'm not a racist! I actually met a Black person once, and he might even remember me. It's the magical data that did it! I am just a conduit."

Do you promote your work on Twitter? Lots and lots of angry leftists, anti-racists, and radicalized people of color on Twitter.