By law in some states, car insurance policies may state that the named insured is required to carry a valid license or the the policy will not be in force. Your son needs to read through his policy to see if it says anything to this effect.
In other cases, the suspended license will not be an issue until it is renewal time with your son's existing auto insurance company. At that time, your son's motor vehicle record (MVR) will be checked and the insurance company will see his driver's license is under suspension.
Other insurance companies may penalize him by taking away any safe driver or renewal discount but allow the policy to continue. In most cases, though, your son will be required to get his license reinstated and show some evidence of this to keep his policy from being canceled.
It is possible, if state laws permit, that your son's policy could be canceled mid-term due to the driver's license suspension. There are a few states (Colorado and Pennsylvania to name a couple) that allow mid-policy cancellations if the insurance company finds the policyholder's license is suspended or revoked.
If your son's car insurance is canceled but he needs to keep insurance on his vehicle, because he has someone driving him in it, it may still be possible to carry a policy on the car.
In this situation, your son should shop for a car insurance company that will allow him to be excluded from the policy and list the person driving him around as the primary driver. That person's driving record will then be looked at for rating purposes.
Once he gets his license reinstated, your son could take this driver off and put himself back on the policy as the primary driver.
When shopping for auto insurance let CarInsurance.com help you or your son get quick quotes. Even with violations on his driving record we can help him check car insurance prices and find you the best car insurance for his situation.