It's not currently enabled there. Can VE be enabled on the meta namespace please? :) I don't think this requires community consensus because VE is opt-in at Meta. However, if needed, I could add a notice at Babel.
Meta-Wiki's main namespace is also a signed namespace. :) Since both main namespace and meta namespace hosts content and discussions, I don't see any reason why we should not enable it at the project namespace as well. IIRC, it's enabled at Wikidata's project namespace as well.