I form of protest to the NBA for poor or fixed scheduling, and poor offciating in favor of LeBron.
Knowing Pop this was more of a protest than resting his players. The term for the labor action in labor economics is 'walk to rule'. You show up for work, but you do not put in a full effort.
Pop's message could be 'hey you rigged this schedule in favor of Heat, and your refs always favor the Heat, so I am not going to play your game and subject my stars to a rigged mtachup'
This is my take.