i just thought of an addon that enables a simple ingame voice chat whisper.
Lets say you and me have that addon active.
then i whisper you a command like "voice"
then the addon on your side creates an ingame "whisper channel" like. "voice-88823" or something, joins it, returns the created channel to me like "you where invited to join voice whisper channel "voice-88823", accept?"
then the addons automatically turns on voice chat for the new channel and we are able to talk.
another option would be to be able to invite other players as well.