We introduced:

• metrics.numCommandsTargetingSystemBuckets and the SystemBucketsMetricsCommandHooks infrastructure to track user commands directly targeting time-series system.buckets collections.
• The CheckSystemBucketsMetrics hook, plus various test exclusions and follow-up tickets:

Separately, SERVER-114496 introduces blocking of external commands targeting legacy timeseries system.buckets collections in FCV 9.0+ (with an emergency server parameter), and that logic must stay for future versions to protect clusters from old tools that still target buckets directly.

Once 9.0 is last LTS, we no longer need to permanently carry the metrics path for system.buckets usage, but we still need to reject direct access.