The only reason I say it is not likely for brake cooling is that there is not one thing other than the look that is sporty driving oriented about the Corolla. The "S" means sport styling...nothing else. It still has drum brakes in the rear maybe the "S" has discs?, soft suspension etc. It was so bad I had to upgrade it just so it was livable for me.
I think it is set up to do different things at different speeds. Maybe like the older Ford Escort grills. Maybe the shape provides a different shaped air curtain at speeds. My 2009 Corolla has smaller but solid front wheel spats. The new one sports a newer design with holes along with many more aero belly panels. Perhaps these interact with those panel additions. If you look at the rear spats, they have changed as well from 2009 to 2014. They sit directly in front of the wheel with no seeable path to the drum brakes, yet have these same rectangular holes. Not sure exactly sure...
http://www.autoguide.com/gallery/gal..._itemId=768434