that should happen with disc brakes too but I'm still not convinced. The majority of force on the spokes comes from supporting your weight and that cycles with every wheel rotation which is faster than you can shift from full forward force on the pedals to full backwards unless the bike is stationary.
with max torque at or close to 0 rpm and max power closer to max rpm.
I agree with the firstpart but I think you are considering the max rpm you usually ride at maybe even the max the powertap records rather than absolute max. I'm willing to bet you can easily spin around 200rpms but highly doubt your max power is anywhere near that.