Hi j112009
Unfortunately, I can't answer your question with any accuracy. Some people have reviews done within 12 - 16 weeks, and some wait over a year or more. You know that your B/F review form has arrived, but nothing further than that. As his claim is due to end soon, I would ring the DWP for an update on the status of his form. You can also ask them to confirm that he will be paid until it is complete.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems