Instead of another big tenant, could the mall not simply be extended so that more individual stores be put in?
That is one option, and will doubtless be considered.
A couple of potential bigger tenants will likely have first kick at the can, so to speak. If that can't be worked out, then you will indeed see the space demised in some fashion.
There are a couple of foreign players who may give the space the once over; but I haven't heard if any overtures have been made.