https://sports.vice.com/en_us/article/if-mlb-really-wants-shorter-games-it-needs-to-figure-out-instant-replay
2016 will have the second longest games, on average, of the past decade. The only season with longer games was 2014, the year MLB introduced expanded replay review.
Manfred has expressed frustration with increasing replay reviews this season. "You can rest assured," he told ESPN, "that we are watching this year, and we will be analyzing during the offseason, both the number of replays and particularly the longer reviews. The four minutes and 50 second reviews don't make me that happy."
It's likely that more extreme measures—like the dreaded 20-second pitch clock—will be on the table for the 2017 season, particularly after that clock's success in shaving off an average of 16 minutes per game in the Triple-A International League. This rule would automatically award a ball to the batter should the pitcher fail to deliver a pitch within 20 seconds.