Am I the only one who would like these to be period pieces? It would be a good way to integrate them into the actual MCU without tones interfering. 1980's NYC, high crime rates; a group of individuals who are tired of it decide to do something about it. As time passes, they fade away, and all that's left is a vague remembrance of the "vigilantes of Hell's Kitchen."
There's really nothing particularly "super" about them. Daredevil's blind, but no one could tell by looking at him, Luke Cage is bulletproof, but good luck proving that, Iron Fist's basically a really good martial artist, and Jessica Jones has super strength and is capable of flight, but the 1980's wasn't exactly the Information Age that we are currently in, and I can see her achieving Weekly World News status at best.
Point is, they could justify why these heroes didn't have the cultural impact that The Avengers did, and you could even set up a Punisher tie-in, as well.