Part of Nintendo's copyright bill on Pokemon X and Y states that "No parties may disclose any information regarding the contents of the product with out legal consent." we've already been told from numerous sources that Nintendo has strictly enforced this.
http://www.gonintendo.com/?mode=viewstory&id=213668
^The same story was covered by various online sources, so whether it's technically Copyright Infringement or not, people can still get in big trouble for it.
The only people that have had legal rights to disclose information on the game are Nintendo, and the people that have been provided review copies. Reviewers were only allowed to disclose certain information, and had to send their copies back after a certain date to help prevent leaks. Obviously, that wasn't enough to prevent leaks.