Can't prove a lick of it: to those who have ears, let them hear. As you well know.
You are disengenuously sliding between the general in your offense and the particular in your requiring 'proof' from others in defense. Poetry is not science.
However, since you asked, and tried to provide a quick hurried google look-up, the Langston Hughes poem, 'Let America Be America Again,' in your second link, is very much in this style.
Moreover, the first thing I thought of, the very moment Amanda Gorman finished reciting her poem was another great inaugural poem, Maya Angelou's 'On The Pulse Of Morning." Also, very much in the same style.
Also, if you read Gorman's poem carefully, and not get stuck on particular cliches you'll find a repitition of cliche-and-subversion--the stating of a cliche and an upending of that same cliche, in language and in imagery-- that is quite compelling.
It's clear that you haven't been exposed to much African-American poetry. No shame in that. But to dismiss it wholesale is rather troubling.