the SIM in the 4S is for international roaming and not used for domestic CDMA use. if you plan on getting a 5, 5C or 5S it will come with a new nano SIM anyways which you will need in order to get LTE on your new verizon device.
in short, yes remove it as it will be deactivated and cannot be reused for the next person. you wont need it either, since it cant be used in your next device.