confirmed on a couple of the mirrorless boards eg 4/3 rumors a few weeks ago
the Sony sensor used in the m5 and m10 does not have electronic shutter capability. something of a mystery why Olympus chose the Panasonic sensor for the m1 though as most reports show is as having slightly worse resolution than the m5 and m10. maybe Olympus understood the seriousness of shutter shake and just got around to the EFC. almost certainly some video benefits