90 year old grandma isn't watching in a bar, she's going to miss the game. I'm sure that she isn't the only one, but I doubt if MLB or the Nats care since she's only been to one game and is hardly a target demographic.
If you are going to a bar I'd call ahead and have them verify that they get the MLB Network and that they know the channel number.
...in fact that's what I advise people to do anytime something is going up against something that's really popular here (NFL, college hoops etc).
Sadly, marketing has trumped pure sports interest - target demographics (people who would subscribe to a premium-tier sports network, in this case) mean more than simple visibility.