It looks like Canon is continuing to research curved sensors, this patent is geared towards light fall off on the sides of the sensor. Patent Publication No. 2016-197663 (Google Translated) Published 2016.
11. 24 Filing date 2015. 4. 3 The central portion of the light falloff is not noticeable to the flat shape The periphery light falloff is noticeable Read more. . . . canonrumors.com