Assuming there is no change in rotor efficiency between 100 and 102, the logic should go as folows:
The power required to hover will be the same regardless of the rotor RPM. The engines shouldn't care what RPM they are driving the rotor at, and the TOT and N1 should be the same (torque will be slightly lower at 102 than 100, as power is torque times RPM).
The change in TOT you see as you bump the RPM to 102 should be transitory and return to the original value when everything settles down.
This, as was first stated, assumes the rotor doesn't change efficiency between the two RPMs.
The reason for the higher RPM is more than likely for OEI considerations as you state.