Note: From the time since I originally posted this link, DuckDuckGo has clarified the status of search filters, and the article has been revised to reflect that. Thus, I’ve edited the Wayback Machine link to show the revised article. I apologize for any confusion, and I hope this clears things up!
So, a documentation issue along with ongoing bug fixing and the OP article is just sensationalist BS? Or am I reading this wrong?