whatsnew note added - 1.4

Author: shubham11941140

doc/source/whatsnew/v1.4.0.rst

@@ -816,7 +816,7 @@ Reshaping
 - Bug in :meth:`DataFrame.stack` with ``ExtensionDtype`` columns incorrectly raising (:issue:`43561`)
 - Bug in :meth:`Series.unstack` with object doing unwanted type inference on resulting columns (:issue:`44595`)
 - Bug in :class:`MultiIndex` failing join operations with overlapping ``IntervalIndex`` levels (:issue:`44096`)
--
+- Bug in :class:`replace` results is different ``dtype`` based on `regex` (:issue:`44864`)
 
 Sparse
 ^^^^^^