It is kind of embarrassing, but I do not know how flagrant fouls (or punches, etc.) are handled in the NBA. In European leagues, if the TV-pictures show some suspicious conduct, the player can still be banned, even if the refs did not see it in the actual game.
If that was the same in the NBA, then the only improvement brought by this new rule was, that player are more likely to get tossed of the game right away, instead of being able to end the game in the normally (but being suspended later anyway).