I suspect it has more to do with how much that school of fish has been harassed recently than anything else.
I have no delusions about sneaking up on fish with an electric motor any mor than with a gas kicker. I also recall that column in "Walleye Insider". Their testing a hydrophone pointed out that the quietest propulsion under water was the jet drive.
I live on a big reservoir. The number of days my 65lb thrust electric will control the boat are few. I still use my 10hp kicker more hours than my main engine every year. On this water, more than a single boat in a quarter mile of shoreline is considered crowded.
I also once worked with an avid SCUBA diver. He had observed, in a heavily-fished MN lake, that even the sound of a depthfinder would make fish bury their noses in the weed cover. A silently drifting boat, however, had no effect on the fish's activity.