It might take several generations, but all of the head injuries are likely to reduce the popularity of football in the long run. More and more children are turning to other sports or choosing not to play sports at all. American football won't be as popular in the future as it is now.
The simple truth is that when something serious should be addressed it won't challenged if it is a society's staple. Americans love their football and very little will make them or team owners give it up. So the country will go through the motions of being "concerned", platitudes will be offered, and maybe some helmet updates but the populace will still fill those seats as religiously as they always did. Honestly, I doubt anyone will care in the first place.
Being a professional athlete comes with significant sacrifice and risk. For that, they are often paid a great deal of money. People enjoy seeing others do things that are extraordinary, even if those things cause injury or death to the person doing them. The large numbers of wrestlers who die young has not deterred people from watching. Brain injuries will not stop people from watching NFL.
There has already been several studies and evidence of the head injuries and their effects caused from football and other sports. There has been no decline in the interest in the sport. It is a big past time in this country and I feel that unless people know someone that has personally been affected, they will not think twice about going to a game or watching it on TV.