In 2021, without any discussion I can find, Leaderboard added This is a wiki that has opted in to allowing global sysops to work here without any discussion I can find. This wiki does not actually meet the default provisions for allowing global sysops (it has 137 admins, and 49 active), and was added to the global sysop wikiset in 2010 (m:Special:Log/1079847) without any apparent local discussion. Likewise, the reference to global sysops at Project:Administrators was added in 2010 (Special:Diff/307909) again as a factual statement without any apparent local discussion. I'm in the process of doing an audit of which wikis are global sysop wikis which is going to end up posted at m:SN#Global sysop set audit.
Personally I think it's fine to have global sysops here, but in order to keep the records straight we should formally codify that somewhere. So, what does everyone else think?