On the latest Collider Heroes videocast, guest Umberto "El Mayimbe" Gonzales from Heroic Hollywood talked about the possible future for Marc Spector. About 10 minutes into the video they are talking about the three mystery films Marvel talked about for 2020 and Moon Knight was mentioned. But Gonzales said he heard that the character was being looked at the same way as The Punisher, bring him onto another series as a "back-door pilot" and then spun off on his own.
This makes a lot of sense as Moon Knight fits in with the characters that Netflix is using and would be a good addition to the Defenders line-up. Or, with Rich Johnston reporting the Iron Fist may be in trouble, Moon Knight would be a good replacement series.