It's more of an anomaly than a "stat," but I'm glad you find it interesting.
Look, Kurt Warner led the league in passing TDs and won a SB in 1999. He threw for 41 TDs. That's the last time the MVP won the Super Bowl the same year. Nine more MVPs have made the SB since then and lost. That's a stronger trend than yours, but it doesn't really have anything to do with how the games themselves unfolded. But, whatever helps pass the time.
NFL Passing Touchdowns Single-Season Leaders | Pro-Football-Reference.com