In OCPBUGS-18984, I think trking has summarized it pretty well:

Docs impact will be a bit broader than a release note.  We have Have a recent etcd backup in case your update fails... wording that we've been dragging around since 4.2. We probably should have adjusted that when we landed the automatic pre-minor-update backups around 4.9, but we didn't. We should have adjusted it when started taking backups for every update in 4.11, but we didn't. Now is the time to revisit those docs. Do we still recommend users do anything manual etcd-backup wise before any updates?

 
It would be great if we can review all upgrade related docs and advise customers to proactively take a backup. 
 
With the introduction of automated backups in 4.14 as TechPreview, we should be able to give administrators and even easier solution.