New 645 lenses roadmap signals (once again) the death of "FF" dreams

Actually I thought the DA designation was for lenses optimised for digital and without an aperture ring, while DFA was for lenses optimised for digital with an aperture ring. All (?) of the former so far are designed for APS-C (correct me if I'm wrong) while the latter have covered a 35mm image circle, but there doesn't seem to be any reason why Pentax couldn't bring out a 35mm DA (ie a lens without an aperture ring).