It’s usually available for streaming as soon as the game ends.
I found out during one of the recent games that there appears to be a “Start From Beginning” option if the game is still being played. Not sure if they do that for all of the games or if it just happened to be that one. I started streaming 30 min late and thought I was going to have to wait until it was over to watch the whole thing. This was the first time I saw the “Start from Beginning” option.
NOTE: This is all on Apple TV with subscription through Xfinity. YMMV.