Google's live stream box in search was mostly found in carousels or thin list view interfaces. But now Google seems to be showing them in a more prominent manner for some queries. Maybe this is not new but Khushal Bherwani is pretty good at spotting new things and he said this is new on Twitter.
He noticed this interface:
I don't think I've seen a live stream box like that before.
Here is what I see or saw when I took the screenshot a few days later (click to enlarge):
And here is the mobile design I see:
Here is the old carousel look:
I suspect this is not 100% new but live streams are rare to see in Google Search and then to see it so prominent is super rare.
Forum discussion at Twitter.