There should be a way for an admin to contact a person responsible for a PDB that is blocking an upgrade. Introduce a new annotation to have an ability to declare PDB ownership. For example:

annotations:
  workload.openshift.io/maintainer-email: john@doe.com

We should describe the use case for this annotation in our PodDisruptionBudgetLimit and PodDisruptionBudgetAtLimit alert runbooks. The email should serve as a quick contact point to a person who can fix a PDB / application that is blocking an upgrade.

This should also be documented in the OCP documentation in PDB and node maintenance sections.