I see it as an admission.
They think they are saying “it would diminish you were I to say ‘here is a great black person’ so I’ll remove the ‘black’ part, and you’ll just be a great person!”
What they are actually admitting is that diminishment isn’t the problem. Race is.
One could just as easily solve the diminishment problem without race-neutering me: “you’re a great person who is black.” But he doesn’t.
Why? Because that still leaves him with the black problem: I see your color and that causes me to erase your color so that I don’t judge you for your color. It’s the gift that keeps on giving.