Not exactly sure how I feel about this. Could potentially punish player/team for actually being injured. The key here is after the ball has been spotted. So, you can’t go down when the other team is already lined up. Coaches are probably going to start instructing players that if they’re hurt, even if not entirely sure, go down right away.
The MAIN issue I have is that you can still fake injuries this way. Opponent gets a big play? Fake an injury right after the whistle. Can’t hurry up, still get your free timeout.