Wrath of Khan was released and looks great.
The others have too much DNR applied, as is the case with many modern Blu-Rays.
My prediction is that this will be the only Blu-Ray release of the theatrical versions of The Motion Picture, Wrath of Khan and The Undiscovered Country and any future releases that improve on the quality issues raised with the transfers of I and VI will be the extended/director's cut versions instead of the theatricals.