As far as i can tell the shield wall is out. WHile it is true that it was a dying formation (being replaced by pike walls) at the time it was still rather commonly used in the early midieval ages. Despite Norman conquest, England was still very anglo-saxon and expecially levy units still used the formation. It also remained prevalent in most Norse cultures like Norway, Sweden, and Denmark. Im not sure about Russia or Lithuania but i wouldnt be surprised if it was still in regular use there as well at game start.

Despite the fact that the formation quickly died out from common use after the start date, I think that it was a good formation that should have been kept if for no other reason than for the use of modders. Then again maybe it is still in. We wont truly know until we get the unpacker.