People are giving a single game way too much credit in how it illustrates the "new" NFL game. It was just a single game between two teams who have very good offenses - and subpar defenses - this year.
NFL teams are averaging 24.2 points per game this season. Yes, it's the highest it's ever been but it hardly makes 54-51 games the "new norm." In 1946 NFL teams averaged 23.6 points per game, that didn't signal the beginning of some new offensive explosion. Just a changing game that took defenses awhile to catch up to.