Yes this is true^^^ I know this due to the wheels I have had shaved before for big brake kits and so forth.. The only way this could be a issue is if it was a heat treated alloy which then again I think you would still be fine..
But also Mike is right to as were you can yes only shave to a point that after so much mill's of material shave will weaken the wheel..
But you got this I want to see this get done, and like now..