Howdy all,
I want to thank you all for the feedback.
I'm an engineering manager here at Evernote and one of my teams is responsible for rebuilding this functionality. Due to a security-related bug in the Ghostscript software that underpinned this service, we made the decision to disable it while we worked in parallel on a suitable replacement. We didn't make this decision lightly and keeping your notes secure is one of our first principles. We're working hand in hand with our security team to ensure the new solution adheres to that principle.
While we've been hard at work re-architecting this functionality, I understand the process has not been fast enough for those of you who rely heavily on it. To that end, I'm doubling-down resources on this and we expect to have a working replacement very soon.
In the mean time, our desktop clients (Mac, Windows) support local PDF thumbnail rendering for those of you who have that option