What I can tell you as I have said before on this thread is that the development is awaiting the redesign that the new bridge has brought about and secondly that the Crypt site hosts a scheduled ancient monument which
I understand is a drain. that is what has caused it to be delayed in the past.
I am sure tha DDC know a lot more about it but I have seen two sets of plans for the redevelopment of all that area and am waiting a third, so believe that something is in progress.