Without any official update or support change, Google seems to have enabled private YouTube videos as well as live streams on the Chromecast. The update was first discovered by Android Police and it appears as though both are working just fine.
The instructions that Google provides in regards to YouTube casting seem to apply to all videos, include private ones and live streams. So, if you are in your desktop browser and decide to play a live stream on a larger screen, you can checkout the support page for all of the instructions.
Eventually, it is likely that the YouTube for Android app will also be changed in order to support the new functionality. Though at this point, the streams are still incompatible with Chromecast.
You may continue to use your phone or tablet to perform other tasks while your video is playing. To play, pause, or navigate with the scrollbar, use your device as you normally would to control playback. If you want to ‘cast’ the video back to your phone and tablet, simply press the ‘Cast’ button once more, and select your phone or tablet from the list of available devices. – Google
Just as before, the main restriction present with Chromecast is that a video must be enabled for mobile playback in order for it to be compatible. That being said, the vast majority of videos are mobile-ready, since a video creator would lose quite a bit of traffic if they were to turn off that functionality.
According to Android Police, private videos can be cast from the mobile app. Live streams are the only type of content currently facing the desktop restriction.
Question – Is live stream and/or private video casting working for you?
Summary: Google has updated Chromecast to allow private YouTube videos and live streams to be cast. Live streams must be played from a desktop however.
image credit: 9to5google
source: androidpolice