I know a potential answer (and probably what's the official stance right now) would be when and if it graduates to site, but perhaps this needs further analysis.
For popular sites there are already a lot of users with 1000 rep that can vote to close, and several with 2000 that can vote to delete -- they are not numbers that hard to reach.
Should there be another metric to decide to up the rep requirements? If so, what would this metric be?
When a site has Pro Tempore moderators assigned, is it really necessary to have so many users with the ability to vote to close, delete, see flags, etc?