It would be an interesting dynamic for the MCU, where major world-ending events are super public and open to judgment, and it could result in a compelling examination of the heroes and their willingness to do what they do best while receiving zero recognition for it (while also setting up big time secrets that could be exposed further down the line in the name of drama).
In the comics the lineup features Captain America, Black Widow, Moon Night, War Machine, Valkyrie, and more, but the reality is that this idea could be executed with any characters.
Inspired by the comics line that began back in 2010, Secret Avengers could wind up being the Marvel Cinematic Universe’s answer to the Mission: Impossible or James Bond movies and feature costumed heroes operating in the shadows and carrying out missions that the world at large knows nothing about.