I believe that’s a real disappointment for Amazon Webstore users. And a good chance to obtain a better solution also, e.i. Shopify or Bigcommerce. Considering their support of FBA, the transition from one platform to another one can be rather painless. As for means of migration, I’d prefer hiring a freelancer or choosing automated migration, like the one Cart2cart offers. Freelancer would cost considerably more though. Good luck everyone!