Back when we ran the Citus cluster on EBS, we lost some EBS volumes as well. This manifested as disk not responding, followed several days later by an email from AWS with the subject Your Amazon EBS Volume vol-123456789abcdef telling you the disk was lost irrecoverably.

But yeah, you need to be ready for your disks to go away no matter where they are: ephemeral, EBS, physical, whatever.