Did Riot remove good behavior banners for the simple reason: too many players got reported for toxicity even if they had good behavior banners. RIot made normal "positive" deduction that there is no false reports of toxicity, but false report of team work. And they tell us to stay positive with their totally negative mindset.
It is interesting I belong to 5% who had team work banner and 5% who are deemed toxic. Maybe it is becuase those toxic players never report each other, and they report those, who are trying to play team. Those who dare to challenge their toxicity. Those who try to talk team to team work. That never occured to Riot.