Defaulting a value for a new boolean field added to an existing content type with content?
If the field has a default value configured, you may be able to cause the "Pinned" field to be populated by bulk editing the nodes from the content overview page, and toggling a different value like 'Published', 'Sticky', or 'Promoted to front page'.



For a programmatic solution, implement hook_post_update_NAME to load the necessary entities and update the new field with the required default value.