Chroma from luma happens to work particularly well for video game content. It's one of the reasons Twitch is interested in using AV1 as soon as possible. Here's a talk by Thomas Daede where he discusses chroma from luma:

https://www.youtube.com/watch?v=yKEDf5-2sT4

Slides: https://people.xiph.org/~tdaede/demuxed_av1_2017.pdf

Twitch is also interested in AV1 for its s-frames feature which allows for better compression in low latency live streaming:

https://www.youtube.com/watch?v=o5sJX6VA34o

https://www.youtube.com/watch?v=AeSNW2T7QwE