Campaigns cannot be updated in bulk. The option to select multiple campaigns and archive/unarchive in bulk has been removed.
Studio | Campaigns
An issue has been found where campaign filters were ignored when selecting all listed campaigns. Any bulk actions (i.e. bulk archive/unarchive) were therefore applied to all campaigns as if the campaign list were not filtered. Until this issue is resolved, all bulk actions for campaigns have been temporarily disabled.
This issue has now been resolved by Product Engineers, and moved to Complete on the Known Issues Tracker.