The problem is that I'm not sure "a third party" has a great track record either. Seems like something more like a judicial system is appropriate if policing enters the picture: right to face accusers, adjudication by peers, standards for proof, right to appeal, and so on.
What counts as a "news article"? Does a blog count? Does it have to be a "traditional" media outlet (eg. tv station, newspaper)? Do op-ed/letters to the editor/"contributor" sections count? How does reporting by a third party vet anything, if they're just repeating the person's claims? eg. "Local business is racist, customer claims" provides the same information as a yelp review saying "this business is racist!".
But these third parties already have a bad reputation concerning these issues. Problems like sensitivity readers are an example. The issues wouldn't be racism, it would quickly extend to businesses lacking sensitivity, whatever that would entail. It would lead to insatiable demands while reducing diversity of opinion.
