Quote from the original news item:
"Quite apart from all the obvious issues, it seems that powering the receivers, transmitters and actuators is something of an issue in the lost-engine-power scenarios that Gulfstream are looking at."
He's hit the nail on the head, of course.
This "fly-by-WiFi" would only "solve" the control signals being physically cut. Anything else would still be vulnerable as before.
Looks very much like a "solution looking for a problem".