I saw this thread and ran a few thought experiments and this is the conclusion I came upon.

The inner ring of outer bearings of the spinner do rotate relative to the inner bearing. There is obviously going to be some slippage due to the fact that there is no such thing as a frictionless bearing but the reasoning sound.

Now onto whether the rotation of this ring affects the rotstion of the whole spinner. Consider this thought experiment. Imagine you removed one of the outer bearings of the fidget spinner and through the hole created inserted a rod that was the same diameter of the void where the bearing was. If the spinner's axis of rotation is centred in the inner bearing, does rotating this rod induce a net torque on the fidget spinner?

I believe the answer is yes. The reason being is that the friction of the rod while turning in the hole is equal at all points, it has a greater torque further from the axis of rotation of the spinner than closer. Because in a fidget spinner the inner rings of the outer bearings turn counter to the direction of rotation of the spinner, this net torque acts counter to the direction of rotation of the spinner.

I'm not 100% on my reasoning here. If you have any doubts please let me know.