I agree that the vouchers will probably go away - as will the ability to change Light tickets for free, given the only KLM/AF does that (even DL doesn't.)

Although I do wonder - the refundable vouchers had a sunset date when they were introduced, and there is currently no sunset date for the vouchers. The voucher option is listed on the booking page where they show all of the types of fares after you have selected your flights. There is a "**" next to the "non-refundable" verbiage that says " Refundable in form of a voucher if you cancel before the 1st flight in your trip. Voucher is valid for 1 year from the date of issue, non-refundable and non-transferable."