BA's problem is that can't scrap a Concorde, its too big a part of the UK nations heritage. It would be a
PR disaster, and they know that. This was why BA chose to save all 8 of their a/c in 2003 and not just the 7 that were part of the flyable fleet.
The Knowledge gained from Concorde stored in the open is that they are no major corrosion issues 20 years on, when the external T5 options have drawn blanks in a few years, BA will look to move it from LHR one way or another.