Andy. Why would it have to be bigger? Swarovski managed to pack all the new technology including field flatteners in their SV 8x32 with out making it much bigger why couldn't Zeiss?
SF42 isn't just about cramming all the technology in, it is about distributing the weight to achieve a certain balance, and having enough length to allow a good close focus with a focusing lens that is doubling-up as part of the objective group as well as just focusing. I too am curious as to how this might be achieved in a 32 without it being longer than desirable. SF42 is quite long and you could argue that folks put more emphasis on compactness when considering a 32.