User blog comment:Mira Laime/Moderators Without Borders — a New User Group is Coming/@comment-209.58.160.80-20170829192250/@comment-5811199-20170905235744

Global Discussions Moderators won't be intervening with any local decisions, they will work with the local admins there to work out a good strategy to help and improve their Discussions.

It's like an extra resource that admins or inactive wikis can choose to use - if a wiki doesn't want them at all, they won't interfere.