There is one quick and easy way to tell if the linear polarizer affects the metering.
Point the camera (preferrably mounted on a tripod) at a light colored indirectly illuminated wall. Rotate the polarizer while watching the metering indicator in the viewfinder. Since the light reflected from the wall is essentially unpolarized, rotating the polarizer will have no effect on the light reaching the lens. If there is any change in the metering indicators then the polarizer is affecting the amount of light reaching the sensor. If you see no change, you're good to go.

FWIW my Nikon FM and Contax RTS II are unaffected by linear polarizers.