Hmm, I found this image out there of someone with a 46-36 MB-labeled chainring mated via bolt covers to an Ultegra 6800 generation road crank. I haven't looked it up, but I'm guessing that the 46-36 MB chainring pairing is just the 6800 generation version of the current 46-36 MT.

Other than the minor cosmetic differences in the 6800 vs 8000 generation crank, this is about how my bike should look once the bolt covers arrive and I get this 46t ring installed. I do lament the disruption of the Ultegra road crankset aesthetics, but not enough to make me not go with it.