Not done yet as it would cause warnings in WMF-deployed extensions.
Related Gerrit Patches:
|mediawiki/core : master||Mark UserRights hook as deprecated|
|Resolved||Legoktm||T113358 Pass $deprecatedVersion parameter to the invocation of the UserRights hook|
|Resolved||Legoktm||T113357 Remove use of UserRights hook when UserGroupsChanged hook is available|