Protection Against High/Negative Voltage for Arduino
If a sensor has a voltage range higher than permitted for the uC, you have to convert this voltage with a voltage divider, as you mentioned.

The sensor providing a higher output voltage does not implicate the need for a protection against overvoltage (you wouldn't add this feature to a 5V sensor, even though there might be voltage peaks as well). Don't get paranoid just because voltages higher than the logic level are involved. If you still want overvoltage protection you should protect the sensor itself and rely on the sensors specification regarding its output range.