i imagine the problem will be solved by better helmets
Not unless better means different and different means less protective. Supposedly, the issue is the slight movement of the brain inside the skull. No matter how hard, protective, or whatevs, you make a helmet, you can't prevent what happens to the brain when the physics of it (once the brain is in motion, it tends to stay in motion) is what it is. I mean, you would have to fix the brain to the skull, then package that in a helmet that wouldn't cause damage. That isn't going to happen.
Soccer too. Two or three weeks ago, the national youth association that governs youth soccer told soccer clubs nation wide to stop including headers in all games and practices for kids under the age of 15, or something like that.
The sport needs to make the head less of a weapon. That said, even if they did that, it wouldn't fix the problem. Linemen get the worse of it and they are hardly ever involved in the huge high impact hits. Its the large quantity of small little hits.
The sport is going to be like heavy weight boxing is now at some point in the next generation or two.