No, death is not normally covered under GAP insurance.
You should read through the terms of your GAP insurance and speak to your Gap insurance provider to get a definite answer but normally a gap policy does not cover the balance of your automobile loan or lease due to the death of the policyholder or co-signer.
A standard Gap insurance policy would be used to cover the balance of your lease or loan after your physical damage policy for Collision or Comprehensive coverage or an at-fault party's Property Damage Liability coverage has paid out the actual cash value (ACV) due a covered total loss of your vehicle.
A total loss of a vehicle typically comes after a car is severely damaged in an auto accident. It can also be declared to be totaled by an insurer if your motor vehicle is stolen and damaged or stolen and not recovered.
If the policyholder dies and still has a loan or lease on the vehicle then the estate or next of kin of that person or the co-signer would typically need to see about taking over the loan or lease, turning the car back into the lien holder, etc. They would also need to contact the insurance company and notify them of the death and either transfer insurance over to the person taking over the car or canceling out the policy.
There are no death benefits from Gap insurance. If the insured was killed in an auto accident where the car is totaled out and the ACV is paid out than Gap should still cover any balance left of the loan or lease but this is just the policy paying out the same as it would whether the policyholder is alive or dead.