DOCS-14852 update remainingOperationTimeEstimate blurb (#5998)

Author: ianf-mongodb

source/reference/command/currentOp.txt

@@ -1121,7 +1121,8 @@ Output Fields
    :ref:`resharding operation <sharding-resharding>`. The time is set to
    -1 when a new resharding operation starts.
 
-   Only present when a resharding operation is taking place.
+   Only present on a :ref:`recipient shard <resharding-process-details>`
+   when a resharding operation is taking place.
 
    .. versionadded:: 5.0
 

source/reference/method/sh.reshardCollection.txt

@@ -124,6 +124,7 @@ The ``options`` argument supports the following options:
              ...
           ]
 
+.. _resharding-process-details:
 
 Resharding Process
 ------------------

source/release-notes/5.0-compatibility.txt

@@ -128,6 +128,14 @@ output the ``cache pressure percentage threshold`` and the
 ``current cache pressure percentage`` under
 ``wiredTiger.snapshot-window-settings``.
 
+``currentOp`` Output Change
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 5.0, the 
+:data:`$currentOp.remainingOperationTimeEstimated` metric is only 
+present on the :ref:`recipient shard <resharding-process-details>`
+when a :ref:`resharding operation <sharding-resharding>` is taking place.
+
 Shell Changes
 -------------