I think you've misunderstood what will happen when exiting the EU for starters - we won't just suddenly be exempt from previous rulings or discard a load of laws.
Secondly EU racers will presumably be affected which means we either exclude them from racing in the U.K., or exclude ourselves from racing in the EU, or have to deal with the consequences of this suggested ruling.
It's a bit short sighted to just say "doesn't matter, brexit"