You're right we should ban images of history altogether. Infact I think we should ban written accounts too. We should go back to the oral historic tradition of the ancient Greeks
He did not say he wanted to ban images, that is an exaggeration. I see the danger as polluting the historical record with fake images (even as memes/jokes), and spreading wrong preconceptions now backed by real-looking images. This is all under the assumptions there are no bad actors, which makes it even worse. I would say; don't ban it, but you morally just shouldn't do it.
The real danger is that this anti-racism starts a justified round of new racism.
By lowering standards for black doctors do you think anyone in their right mind would pick black doctors? No I want the fat old jew. I know no one put him in the hospital to fill out a quota.