GitHub Copilot change history: Copilot Code Review is unable to complete reviews

GitHub Copilot reported a critical Code Review outage starting 2026-09-28 21:16 UTC, resolved at 2026-09-28 22:08 UTC (51 min). Approximately 70% of requested reviews failed across all environments; failed reviews were not automatically retried, so users needed to re-request them from their pull requests. GitHub attributed the issue to a dependent-service change and reported a rollback underway.