I don't think you should have played that...Dan...
In principle this has been tried before on smaller scales. Although I cannot imagine most people's internet connection piping in 4k or 8k streams without "breaking the internet" or at least overwhelming their local connection.
Games are for more lag sensitive than movies - there is a need for upload removing a lot of capability of buffering. Even simple games can stutter and stall on standard internet connections. Beyond that, if you are trying to play people in foreign countries you run into the laws of physics becoming a barrier, not just hardware that could be upgraded. Latency will be a big challenge. This is why, at least in general, large MMO games have relatively simplified combat physics and behaviours over the complex versions that most locally played games have.
Regardless of discussion on Google being an appropriate host... I just don't quite get how this will work for many people to an acceptable standard..