There is a video on OTC Markets pertaining to "dark" firms that don't meet the September cutoff to be current in filings. The video is called "15C2-11 Questions and Answers". It features Jason Paltrowitz and Dan Zinn from OTC Markets. It does a pretty decent job of describing the status of Dark firms and that although far more difficult, they will still be tradeable. It will all boil down to visibility.
https://youtu.be/hKGUo_qvjnw