The "timing" section of serverStatus is added if and only serverStatus was slow. Under some conditions related to server performance misbehavior this can cause frequent schema changes that greatly reduces the compression efficiency of ftdc which in turn greatly reduces the retention period and hampers diagnosing the very problem that is causing the slow serverStatus. It should always be present or never be present. Since it is also logged to the mongod log I think it would be ok to remove it from serverStatus. Alternatively it could be made optional in serverStatus, on by default for compatibility, but removed from ftdc.