It was also the first year of VAR in the league and referees were refusing to make decisions unless a player went to ground, it's no surprise that a team who's main tactics was to run fast and throw themselves to the ground at the lightest touch did well that year by 'winning' games through soft decisions going their way by pkaying on referees insecurities.
I don't think it's a massive coincidence that Liverpool and Leicester have struggled to adapt since referees have decided that contact doesn't necessarily mean foul. Liverpool have kind of got their act together but Leicester have been more exposed by the changes.