This is either a publicity stunt or the NFL has only a few more seasons of life within it. They've already emasculated much of the game. One simply can't make a sport that requires the inherent physical contact completely "safe". Injury is a fact of life in football.
The one rules change that would probably do more to reduce injuries that anything else, because it would require a change in how the players do what they do, would be to remove the facemask. But that won't ever happen.
My father used to say that the single worst change in football was when they started wearing the helmets as opposed to the leather caps he wore in high school football.
Those guys are so pumped full of steroids and so huge and fast that it's inevitable that the players will risk career ending injuries, or if not, risk chronic health problems and disabilities after their retirement.
It's a heavy price to pay for the money.
Think of the famous players who've had careers ended by injuries. Bo Jackson, Sterling Sharp. Then there are the quarterbacks with many concussions.
Some fellow like Reggie White drops dead in his 40s.
Nasty business. They're monsters and they're almost all on drugs.