SB
It is possible that the DWP will re-visit their original Decision in the days before a hearing, they can only make a more favourable Decision in which case your appeal will be lapsed, any new Decision that they make can again be appealed.
The Tribunal will not make any Decision prior to the day of the hearing, however, it is possible that they will make a Decision prior to the hearing, this is becoming increasingly rare but does still happen. If it does, then the Clerk of the Court will try and contact you before you leave for the hearing, but depending on circumstances may not be able to do so, in which case you will be informed when you arrive.
Good luck
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems