Deal announced today.
Here is Roku's press release.
On one hand, the Roku Channel is a free ad-supported channel, so there's no paywall. But I liked NBC Sports' production level and style (which makes sense considering they were literally the first-ever TV broadcaster for baseball).
I still miss the free mid-week YouTube day games they had a few years ago. Very relaxed day-at-the-ballpark feel, and during a time slot where pretty much anyone could have a browser tab open with the game on.