The mediawiki page of Extension:Replace Text reads that This extension comes with MediaWiki 1.31 and above. Thus you do not have to download it again. But when I go to Special:ReplaceText of Marathi wikipedia which has 1.32.0 version of mediawiki yet there is a no page shown.
WMF's sites is different from mediawiki release. Yes, this extension is bound in 1.31+, but Marathi Wikipedia is a WMF site, binding extensions are not necessarily enabled in the production. This requires community consensus to be enabled.
ReplaceText is intentionally not deployed on WMF sites so there is no bug here. Websites are free to have different configurations than the default software.
Closing this task as invalid.