The knee-jerk reaction for any fan is to not just ignore a divisional rival in the playoffs, but often to curse them. That word, rival, is an odd one, since I don’t think the Red Sox view the Blue Jays the same way they do the Yankees, or the Cardinals the Reds like they do the Cubs. In the AL Central, it’s a bit more muddled, since there has rarely been any one dominant team, but there are certain localized animosities.
I’d prefer none of them are successful, but I don’t particularly have a specific hate ray aimed anywhere like they do in Boston or LA or Philly (that last one goes everywhere).