My feeling is that they're almost certainly being rational on that front. The income from broadcast rights (or network ownership, in the case of the Orioles) is substantial.
Even for me as a lifelong baseball fan, I've largely stopped watching games. By the time they do away with the restrictions, will I even bother? Who knows.
But I am a little biased and may be overestimating the impact of cord cutting among millennials
It's useless. So the free streams that are available are amazing.