Brad send this email. Not sure what phab task contains the details. Might affect Pywikibot. Maybe we can rip out some work around code?
The format of block expiry timestamps returned from list=users and list=allusers has long been inconsistent. It was being returned in an internal format (e.g. "20190918201053"), rather than the ISO 8601 format used by the rest of the API (e.g. "2019-09-18T20:10:53Z").
The 'blockexpiry' property from these two modules will be changing to the standard ISO 8601 format with 1.34.0-wmf.24. See https://www.mediawiki.org/wiki/MediaWiki_1.34/Roadmap for a schedule of deployment to Wikimedia wikis.
This change also brings the block information returned by list=users and list=allusers fully in line with that already used for meta=userinfo and 'blocked' errors from various actions.
Brad Jorsch (Anomie)
Senior Software Engineer