The original request behind Scribunto's mw.text.unstrip method was to undo <nowiki> tags, as a mechanism for quoting arguments being passed into a module. But the implementation was more broad, allowing access to the HTML generated by the <ref> and <references> tags, by special page transclusion, and so on. This caused problems such as T63268.[1]
With the merge of Gerrit change 171290,[2] the mw.text.unstrip method will unstrip nowiki strip markers and will replace all other strip markers with the empty string. A new method mw.text.unstripNoWiki is also provided to unstrip nowiki markers while leaving other markers in place, and mw.text.killMarkers to remove all strip markers from a string.
Modules using mw.text.unstrip should be checked to ensure they don't break with this change. A list of modules on WMF wikis including the string "unstrip" is at https://test.wikipedia.org/wiki/User:Jackmcbarn/unstrip.
See https://www.mediawiki.org/wiki/MediaWiki_1.25/Roadmap for the deployment schedule.
[1]: https://phabricator.wikimedia.org/T63268 [2]: https://gerrit.wikimedia.org/r/#/c/171290/