• Annual Fees: Will Amex issue prorated refunds for annual fees if they cancel all cards? I guess not if the fees were charged for more than 30 days, based on data points from last year and according to their terms.
  
• MR Points: Will Amex forfeit all MR points?
  It seems likely that Amex would allow 30 to 60 days to transfer MR points to a previously linked Frequent Flyer Program (FFP). How about link a new FFP and transfer MR to it.
  Also, will Amex forfeit sign up bonus for card opened less than one year ago with opening bonus? Per the terms, if a card is closed within one year of opening, all opening bonus will be forfeited.
  

I'm actually confused. Per the terms, Amex will remove all points if they cancel the accounts according to the terms available at American Express Membership Rewards Terms & Conditions,
When we cancel your Card Account
If we cancel any of your enrolled Card Accounts for any reason (including your death, insolvency or bankruptcy), you'll lose all the points in your Rewards Account.
However:
• If you die, the executor of your estate or personal representative may be able to make a one-time points redemption bycalling 1-800-AXP-EARN (297-3276).
• If we cancel your Card Account due to inactivity, you'll have 90 days to use the points in your Rewards Account before losing them.
• You won't lose points if we cancel your Card Account by accident