Aren't there several kinds of ground simulators: those used by pilots for their regular training, and some Airbus industrial simulators ? for design & research, with a finer modelling (possibly also accurately describing the aerodynamics outside the flight enveloppe) and maybe a greater flexibility to set up some specific scenarii ?
How could an accurate simulation be created of unknown situations unless the AB test pilots intentionally put the aircraft into those situations, which, in my opinion, might lead to vacancies in the test pilot ranks?
I think it might be prudent to just put notices in the flight manuals saying, "Unknown territory, don't do this!"
Perhaps some results of wind tunnel testing would be informative.