Bitmovin produced an AV1 live stream a year ago using 200 cores: https://bitmovin.com/bitmovin-supports-av1-encoding-vod-live...

And six months ago they had improved on that to do live streaming with 32 cores: https://bitmovin.com/constantly-evolving-video-landscape-dis...

Twitch wants to use AV1 for live streaming. Here's a talk on the "switching frame" feature of AV1 for use in live streaming: https://www.youtube.com/watch?v=o5sJX6VA34o