Due to the global pandemic going on right now, the MLB season is on hold. Although MLB has stated they want to play 162 games this season, if they play at all, that wish gets less likely by the day.
With a shorter season, owners are going to be upset over lost revenue. One easy way to make more money is to have additional playoff games. Right now, MLB is the most selective with its postseason, with only 10 teams making it per season. Compare that to 12 for the NFL and 16 for both the NBA and NHL.