Resolving comments is helpful to whoever is making the revisions. When the person resolves the comment a notification goes out to anyone who was on the comment thread. This could be many emails saying comment was resolved. There should be an option to enables an option if a notification should be sent or not for each resolved comment.
This is managed through the proof reviewers/approvers proof notifications.
They will get notified if a comment is resolved if they have 'All Activity' as their proof notification. If you want the people on your proof to only see when a decision is made or a reply only to their own comments, you set that at the proof notifications alongside their proof role.