T356294: Restrict which groups have access to Special:GlobalContributions expects to implement some form of cross-wiki permission checking in order to ensure that users can only see privileged information they have the rights to. Until then, we want to restrict access to Special:GlobalContributions to members of the global-temporary-account-viewer group (see T375117: Give access to checkuser-temporary-account on all wikis for any user who is in the checkuser or suppress group on any wiki) because that's the only group of privileged users we can guarantee has access to the information from other wikis. We don't want to disable Special:GC until this permission check is done, as we'd like to be able to allow users to test Special:GC between now and the minor pilot wiki deploy.
Based on the following premises:
- Special:GlobalContributions will only be accessible from metawiki (see T376612: Implement Global Contributions as a central page on Meta and implement redirects from other projects)
- No one needs IP reveal rights on meta, as meta only knows that temp accounts exists and doesn't have them enabled
- The only local groups on meta with (eventual) access via either checkuser-temporary-account/checkuser-temporary-account-no-preference are:
- checkuser (via extension.json)
- checkuser-temporary-account-viewer (via autopromote in CommonSettings.php)
- bureaucrat /sysop/suppress via core-Permissions.php
- No one will be a member of checkuser-temporary-account-viewer, as the conditional for autopromotion ($wmgDisableIPMasking || $wmgEnableIPMasking) will return false for metawiki
We should then add a config to remove the checkuser-temporary-account/checkuser-temporary-account-no-preference rights from the remaining groups (checkuser/bureaucrat /sysop/suppress) on meta until T356294: Restrict which groups have access to Special:GlobalContributions is done (ETA is by minor pilot wiki deploy in ~1-2 weeks, as it's a blocker).