AF/KLM has adjusted their refund policy to finally comply with the law. Now all flights that have been canceled by AF/KLM can be refunded, no matter the date at which they were canceled. It is also explicitly stated that people that already received their voucher can exchange it for a cash refund. See also the press release:
AF/KLM press release
It's interesting to see that they do not change the conditions attached to the 15% bonus on the vouchers. As it stands I think there are only a very limited group of people that can make use of this and will not want to exchange the voucher for cash.
Now it will be interesting to see how quickly they'll handle these refunds.