For rollouts like this, a small holdback experiment is typical, to assess long term trends. Or maybe your browser doesn't have hardware acceleration enabled? Or you could be in canvas mode?
Try ?force=webgl on the end of the maps url in case it's the latter.
Try shadertoy.com to see if webgl is available.
checking maps on mobile which is on Canadian ISP, in chrome and the google maps android app, i can only see the "flat" map.