Thing is, people will call anything and everything a "flop". There are a lot of players that get great position but will welcome contact with backward motion and a slide to make sure they aren't getting the entire bulk of the contact. It is appreciated by both players. I was taught how to do it, and to be honest, if they start calling THAT a flop, then the NBA is a waste of time as nobody will want to play defence, and it will give the soft as lazy asses an excuse not to play hard defence. If players will be expected to take the entire blow and fall as a result, you will either see zero charges being drawn, which are a direct result of great footwork and effort, or, if they do draw them, a lot more injuries.
I don't like it. I am very wary.