As part of the update, we have fixed an issue that would cause disconnects in Random Matchups and Online Competitions under certain conditions. All players who wish to participate in online battles or use any other functions that require an Internet connection must download the latest update.
^ this has been pulled straight out of the Global Link, meaning it's official. And here's what they've done to achieve that purpose:
This update was released as part of our continuing effort to prevent unauthorized data manipulation in competitive play and to enhance our unauthorized data-check functions. After applying this update, if you play in Random Matchups or Online Competitions and encounter a player attempting to manipulate data in that way, you will be disconnected from the player and the match will end. Matches that end in this manner will not count as a win or a loss, nor will they be counted as a played match or affect your rating. Disconnections that occur through other means will be treated as normal and will affect your rating, so please ensure that you are always playing with a stable Internet connection
Hope I helped!