Rugby, and American Football are only just coming to terms with how dangerous repeated concussions can be. I can't speak for American Football, but for rugby at least, they're trying to take concussion seriously.
I say trying, because there's still a large impetus in rugby culture to minimise/deny concussion, even more so since the rules changed to try to prevent repeated concussions - if you have a concussion, you can't play for at least 20 days since symptoms abated (in my country), which can make a real difference in a team's performance in a given season if you're their star fly-half[1]/winger[2] (for Americans, kinda like the quarterback in that those positions often define the plays made).
Where I can see this being valuable is in detecting concussions that are either a) subtle enough in symptom to slip past the referee's / team doctor's notice, so picking them up via easy testing can prevent further damage (as a concussion on top of concussion is the worst case scenario) and b) pick up concussions that people are trying to deny because it may harm or hinder the team if they're benched.
I can see easy testing for this bringing benefits to both groups a) and b) even if the b's might not be super happy about it.
[1]: Highlights of Dan Carter, probably the second best fly-half in rugby history: https://www.youtube.com/watch?v=D3UsOzJuq5M [2]: Highlights of Jonah Lomu (RIP), arguably the best winger in rugby history, and an absolute machine: https://www.youtube.com/watch?v=OsXTa7UCGlk