I checked with Amex member rewards and the rep pointed out item 8 in their Member Guidebook as follows:

"In the event of a Cardmember's death and the subsequent cancellation of American Express Card(s) held in his/her name, points accrued in the Program Account may be redeemed by the beneficiary designated by the Estate Trustee or Executor. If the beneficiary is an existing American Express Cardmember enrolled in the Program, points may be transferred to his/her Program Account."

While Amex may be onside with compassion, and most airlines appear to be, I understand MARRIOTT goes on a point grab if you meet your maker before your time.