It is worth noting that in several youth soccer leagues, heading has already been eliminated, and checking is prohibited in hockey until U-14. I would argue the soccer example has less impact on the game than tackling in football and is therefore a less effective analogy, but eliminating checking is pretty close to football/tackling. It has its benefits - more emphasis on skating, passing, positional play in the early formative years. I imagine there could be similar benefits for football.
Is this limited by the State the league is in or the league?