So, letīs have a look at it this way:
If you have a propeller which is being rotated then it is an airfoil which necessarily creates lift (thrust) as well as drag. It pushes the air backwards but also causes the air to swirl. One effect is that by law of action and reaction, the torque has to be transmitted to the engine powering the propeller. Another effect is that unless the propeller is a pusher (and the vortex is left in free air touching no aerodynamic part of plane again) there would be some aerodynamic forces where the slipstream hits plane.
If you have a propeller which isnīt rotated, but is stuck, and it is subject to airflow, it creates drag. But if the propeller is a spiral (not pitched to be feathered) it also creates swirling airflow. This means that there has to be a torque transmitted to the engine wherever the engine mountings are stuck to prevent the propeller from rotating - and there also would be a slipstream creating aerodynamic forces if and when it meets aerodynamic surfaces.
If you have a plane with 2 propellers distant from each other, on different axes, and both are rotating in opposite directions, then there are 2 slipstream swirling vortices separate from each other. Both engines would create torques - but those torques would cancel out over the airframe if they are exactly equal.
Now, some planes have pairs of counterrotating propellers close to each other on the same axis They would tend to create swirl in opposite directions - and those swirls would tend to cancel. But if the propellers are coaxial (and close in diameter) then unlike propellers on separate axes, the swirl would be eliminated much more thoroughly (and the energy of the swirling movement recovered!).
It follows that a powered propeller and an unpowered spiral that are on the same axis might also cancel out each otherīs slipstream swirl. Wonder why it is not common on exposed propellers...
In any case, turbofans normally use stator vanes (inside) to keep the swirl of the exiting jet blast minimal.
Now, flywheels are a different effect. A propeller in airflow creates torque when it is rotating at a steady rate, or when it is not rotating and causing airflow to rotate.
But anything with mass, whether a propeller or internal engine parts, create additional torque effects when the speed of rotation is changing - like speeding up or slowing down engines.
But this happens only when the speed changes. If a propeller and the engine behind change the speed of rotation, this changes thrust, slipstream torque et cetera, and also causes torque while the change is going on.
Whereas if a propeller changes pitch while the rotational speed of propeller and engine behind is kept exactly constant, the thrust changes, the slipstream torque changes - but since the rotation speed is constant, there is no extra temporary torque.