This should be a non-issue because they already have player ratings.

One of the main features of player ratings for sports/games/leagues/etc that use them, is that a sudden change in rating should trigger an investigation. Like in competitive chess for example, you can't just show up one day and start playing far better than your rating and have nobody look into how that could have happened.

They should probably just have suspensions trigger automatically and have people barred from all competitive play until their case is reviewed.