While it's possible to simultaneously connect multiple Bluetooth devices to a Chromecast with Google TV, it seems that the current Chromecast firmware only broadcast audio to the most recently connected device.
This behavior is quite the opposite to most modern Android and PC devices, where audio can be broadcasted to all connected Bluetooth devices for sharing multimedia with two or more people with wireless headphones. Given this is one of the latest Chromecast product releases, there was the expectation that's its Bluetooth capability would be at least on par for this modern use case.
For example when two people would like to watch the television without disturbing the rest of the house by listening to cast video via two Bluetooth headphones.
Note: discussion of external hardware workarounds such using third party Bluetooth transceivers are of no interest, as focusing on firmware upgrade that replicates the same Bluetooth functionality found in modern phones is be preferred.
