In SPM-3865, we removed the Global Indexes code from Cluster Scalability codebase. Additionally, SERVER-102756 removed the API to access Global Indexes from the CatalogCache, and SERVER-103708 aims to decouple sharding awareness from the oplog — partially removing some unused code from setFCV and the oplog 'c' entry.

However, there is still a significant amount of Global Indexes code that should be removed to improve developer productivity by eliminating a feature that is not production-ready and that we do not plan to release.