Thread:Talk:Extension default namespaces/Social tools' namespaces/reply (8)

If those people want to install an extension that uses namespace numberss that conflict with their wiki's existing namespaces, they can configure or modify the extension locally so it uses different namespace numbers on their wiki. But changing it upstream would adversely affect way more users.

The only namespace numbers that can really be considered "reserved" are those that are already in use on a given wiki.