Don’t know if this has been proposed earlier: Webcam broadcast of the leader’s pain cave for group rides. The user chooses to have this as an overlay to the regular ride screen. Instructions and commands for the group via webcam and speaker. The ride leader becomes more an instructor comparable to spinning classes.
There are so many different ways to do this, different hardware configurations that support it, various streaming rigs, additional capture cards, dual-machine setups (game in one, stream and capture/encode in the second machine), that I don’t think it belongs within Zwift itself.