You looked up the Wikipedia for post millennial, but couldn’t be bothered to double check archive.org to confirm the language referenced in the article was in fact on the BLM site until it was recently removed? See: https://web.archive.org/web/20190118185735/https://blacklive...
'We disrupt the Western-prescribed nuclear family structure requirement by supporting each other as extended families and “villages” that collectively care for one another, especially our children, to the degree that mothers, parents, and children are comfortable.'
So what? There are tons of cultures in which child raising is communal. Including various parts of Western cultures at various times.
They're not saying "nuclear families suck." They're saying, "nuclear families are one approach among many which humanity uses to raise children, and it's not necessarily always the best."
'Disrupt' doesn't mean 'Destroy'.
They also said 'to the degree that mothers, parents, and children are comfortable.' Meaning, IMHO, 'folks should make their own choices for their own families.'
Considering how incredibly destructive slavery was to any form of family institution (father sold or killed, mother sold, child not, etc), and how that has echoed down to the present day in the black community, I can understand why black folks would want to have that discussion.
Which is not just a discussion being had by black people, either.