We currently hook into MediaWiki to detect changes in visibility attributes for a revision, including whether the author's name should be visible. However, RESTBase is unaware of when a user is blocked/suppressed across the entire wiki, and continues to make this information available.
This issue has a lot of moving pieces, so I'm going to start laying them out, and creating subtasks as necessary:
Consume events, persist a suppression set
As events are produced, a consumer will be needed to update a set of hidden users. Lookups against this set must be fast (they will be in-lined with every request that exposes author information).
Suppress user information
RESTBase will need to be updated to utilize the suppression set, and filter out user information accordingly.