It turns out not to be about racism, at least not in the way you think. He talks about the impact of white flight on the community - significantly because white people didn’t want to live and educate their children with black people. And they don’t choose to worship with black people either.
But black people, by necessity, have gotten comfortable being the minority in all spaces, so they are much more likely to attend majority white churches than vice versa. The result is to threaten the very existence of black churches, even in the inner city. That potentially threatens the exit of those churches and results in a loss of community cohesion.
It’s a valid point even though it’s done in an intentionally provocative way.