Is this against the rules??

[JRutledge]

This is not the same situation as trying to get around the screen. We have a player just leaving the court for no reason at all or the reasons that the rule was changed to call a technical foul. All the examples the NF uses for the new rule deal with getting around a screen, not leaving the court during play to gain some kind of advantage.

According to your point of view I am going to assume that you are going to stop play with a violation, give the ball back to A and then continue play with throw-in? Where does it say to do that?

"Typically, this play is seen when an offensive player goes around a low screen, runs outside the end line and returns on the other side of the court free of their defender. The violation will be called as soon as the player leaves the court. The committee hopes that changing the penalty will increase the likelihood of the infraction being called and eliminate this tremendous advantage."

Casebook play 10.1.9 fits this much more than you are describing. The player did not return to the court in a proper manner after a timeout, not because they wanted to avoid a screen or during play to get an advantage. They left the court because there was confusion as to whether they were supposed to be on the court in the first place. This is a totally different situation than trying to avoid a screen. I think you have read this new rule so much you forgot to read other situations that might apply.

Peace