Mingon,
All Tbred pictures have a core that is rectangular, rather than the more square shaped Palomino core chips. from this pages core measurements from a week or so ago, "width" between the Palomino/Thoroughbred core was more or less the same, but the "height" is significantly different, which accoutns for why it looks wider.
It is still 80sq mm in contact surface, no change from earlier numbers.
Mike