Google announced audio news for the Google Assistant. This is not speakable markup. or YouTube videos playing on the Google Home Hub, this is real audio news, like broadcaster, podcaster, etc that produce audio form content.

Google said they are opening a developer preview that you can fill out a form over here to participate in. Google said:

Here is the content guidelines for this audio news format.

So if you do podcasting or broadcasting, might be worth exploring.

Forum discussion at Twitter.