This time of year, you do get the pages for things that were always broken, but nobody noticed before, because they only show up when the system has been running without changes for more than two weeks.
No deployments revealed how a legacy background processor started losing connections to the message queue and gets stuck in a state where it never reconnects.
Deployments always cycled the pods before the issue manifested.
[0]: https://github.com/kubernetes-sigs/descheduler#podlifetime