What doesn't make sense? Xfinity and all cable companies are losing customers at an accelerated rate. One of the biggest reasons remaining customers keep their cable is for live sports. If the customers can just get it for free over the air, there is no reason to keep or sign up for their service and cable will die even sooner.
The NBA finals were over the air because they are the NBA Finals. The World Series will be over the air as well. CBS, NBC, ABC, Fox aren't airing random regular season NBA or MLB games on a weekday night.
Back in the day, they always blacked out the internet feed during games and you had to buy the radio version of mlb.tv (mlb at bat?). I noticed a year or two ago they just began airing the games on the feed. Interesting that they are choosing to enforce that again.