We will be setting the oplogTruncateAfterPoint continuously in mode PRIMARY so that we can safely replicate before journaling. SERVER-41389 will pause the thread that sets the oplogTruncateAfterPoint in mode SECONDARY, but we are not guaranteed to run batch application, which unsets the oplogTruncateAfterPoint, before potentially stepping up to primary again.

UPDATE: we are pivoting to unsetting the value on stepdown, as opposed to removing the invariant on stepup.