Is there such a thing as 'eBike specific' freewheel?
I agree with you that a hub drive e-bike should not impose any more stress on a freewheel than a conventional bike.  Whichever wheel you drive, the torque supplied by the motor is not going through the freewheel.  The torque transmitted by the freewheel is all generated by you, just as on a conventional bike.  A stretch would be to claim that you can generate lots of torque in short intervals, then let the motor drive you in between, while on a conventional bike you would have to be working all the time so the torque peaks would be lower.