"Shortly thereafter, in March, Facebook’s world exploded, when it was revealed that Cambridge Analytica had gotten access to the profile information of millions of Facebook users, going through what was considered an “official route” in 2012. Facebook stopped bothering us about our PYMK Inspector, and the tool currently remains up."

likely they still have an issue with it, but as the article implies they are busy with other issues/data scandals to make a further issue with the "tool" at this time atleast.