I wanted to share the official announcement for this:
Summary
PyPI’s implementation of the standard index APIs now includes project status marker information. Downstream consumers of the index can use this information to inform users and set policies when packages enter noteworthy states, e.g. archival or quarantine.
Do I need to do anything?
No! This is a compatible extension to the index APIs, existing consumers do not need to make any changes. However, the PEP encourages installers to emit deprecated warnings on certain statuses. I’ve opened issues to coordinate the implementation of that.
For consumers that mirror the index (e.g. private mirrors), you may want to propagate these statuses so that users of your index see the same statuses as they would from PyPI.