Or in fact by a reduction in the upward force due to the reduction in pitch angle and AoA as explained earlier and the reason it is around the 90 degree mark.
Can you explain in more detail, why you think that pure aerodynamic forces applied as a sinusoidal function of time would not lead to 180 degrees phase shift?
0 degrees - - >acceleration proportional to force
90 degrees - - > speed (integral of acceleration)
180 degrees - - > displacement (second integral of acceleration)
And you have completely forgotten the periodic drag changes as the blade spins round (the reason rotors have drag hinges or dampers)- something a gyro doesn't have - there are more differences than similarities between a rotor and a gyro but you can't seem to see past the spinning bit. Each blade speeds up and slows down in its journey because as CL increases due to increase in AoA, so does CD (coefficients of lift and drag respectively).
What would a gyro do if you sped it up on one side? It can't because it would speed up the other side too - unlike a rotor.
The drag and coriolis effect are a order of magnitude smaller than the lift effects for normal operation. They have virtually no appreciable effect on the phase lag of the tilt of the rotor cone.
After all a gyroscope is not ideally stiff. It is also subject to microscopic deformations. And forms a very minute cone from gravity. This cone also leads to coriolis effect when tilted. This will lead to tiny elastic deformations
Even sound waves lead to tiny displacements in a gyroscope.
I think we are not talking about absolute purity, are we?
A gyroscope is only a sample implementation. It does not define the gyroscopic effect.
Thats like saying "this is not true friction, if it is not exactly like a brake pad" or "this is not true bernoulli effect because it is not exactly like a venturi tube"