Checking mw.config.exists('wgRelevantUserName') as a non-sysop account/IP will return:
- False on Special:DeletedContributions
- True on Special:Block
I'd expect there to be agreement here, since there's no page content that a user can interact with on. Not sure if there are others that are divided; Special:UserRights shows the log and lookup to everyone so it makes sense to return true.