When a reviewer creates a markup, they are likely not the person who picks up that markup/makes the change. They should be able to assign that markup to someone, which could then be notified that they have markups. That person who is making the change should then be able to change the status of the markup to complete. The reviewer would then be able to accept that status change and close/archive the markup.
Basically, take some of the functionality of Issues but without the need for a pushpin, root cause, etc.