In my time, I have brought it up as something we could've added back to TFTV. The logistics are there to make it possible, it's simply the teams aren't willing to cooperate with something so trivial as comms.
In an ideal world we wouldn't just want audio, I'd love to intergrate player cameras into the HUD so that we can put faces to player's outside of just LAN events, innovation we are years behind other esports with.