add description to whatsnew and revert unwanted changes in datetimearray docstring

Author: annika-rudolph

doc/source/whatsnew/v3.0.0.rst

@@ -421,7 +421,8 @@ Missing
 MultiIndex
 ^^^^^^^^^^
 - :func:`DataFrame.loc` with ``axis=0``  and :class:`MultiIndex` when setting a value adds extra columns (:issue:`58116`)
--
+- :func:`MultiIndex.get_level_values` accessing a :class:`DatetimeIndex` does not carry the frequency attribute along (:issue:`58327`, :issue:`57949`)
+- 
 
 I/O
 ^^^

pandas/core/arrays/datetimelike.py

@@ -1798,7 +1798,7 @@ def strftime(self, date_format: str) -> npt.NDArray[np.object_]:
     ----------
     freq : str or Offset
         The frequency level to {op} the index to. Must be a fixed
-        frequency like 'S' (second) not 'ME' (month end). See
+        frequency like 's' (second) not 'ME' (month end). See
         :ref:`frequency aliases <timeseries.offset_aliases>` for
         a list of possible `freq` values.
     ambiguous : 'infer', bool-ndarray, 'NaT', default 'raise'
@@ -1836,6 +1836,11 @@ def strftime(self, date_format: str) -> npt.NDArray[np.object_]:
     ------
     ValueError if the `freq` cannot be converted.
 
+    See Also
+    --------
+    DatetimeIndex.floor : Perform floor operation on the data to the specified `freq`.
+    DatetimeIndex.snap : Snap time stamps to nearest occurring frequency.
+
     Notes
     -----
     If the timestamps have a timezone, {op}ing will take place relative to the