In SERVER-69959 majority committed point advancement notification mechanism is introduced. Now change streams that are reading through oplog and change collection (in serverless) can benefit from it while waiting for the insertions of the new oplog entries (which are majority committed).

Originally change streams (that are reading the oplog) were relying on the `signalOplogWaiters()`mechanism, which was called once majority committed point advanced. This ticket's purpose is to investigate whether or not this method can be removed as it is no longer needed for the change streams purposes.

Evergreen patch with `signalOplogWaiters()` being removed.