The release of a new set means a time to revisit the rules. With Magic Origins, it was time to rethink drawing extra cards. After a high profile incident at Pro Tour Dragons of Tarkir where this rule was forced into a spotlight, the following change has been made.

From the announcement:

Here’s the big one. Traditionally, Drawing Extra Cards has been a pain point. Because of the hidden information involved, it’s hard to notice, hard to preempt, and hard to fix afterwards. As such, as long as there’s been guidelines, drawing an extra card has been a game loss, even though that penalty is out of proportion to the actual impact of the error on the game. Over the years, we’ve tried various definitions to try to mitigate the worst situations, but all efforts have either been such that it never gets applied, is difficult to understand, or produced results that seem too harsh. Now, we’re going to try something different. Drawing Extra Cards is a Warning, accompanied by revealing your hand and having the opponent choose the excess cards to shuffle back into the library.

The change is designed to "mitigate the advantage." It is noted that the player can respond to the infraction by conceding the game, but the Warning is still noted.