Hi,
As I mentioned in the other thread, the Sony 50 MP sensor is being phased out. There always comes a time when a part supplier says The End, My Friend. Then it is time for a Last Time Buy of the part and one has to begin anew with R+D.
So, the easy choice is the 100 MP part. So, I expect to to either see a 645Y come along or the end of the 645Z with no replacement. I doubt they will just drop off the medium format map. So, I look for a 645Y.
And, I don't need a NDA to figure this. I've been in R+D since 1981. This is how these things go. Part A becomes unobtanium and so we need a New Part . And then we add new features and make a new model. 645Y is my own take on a model number. They might call it 645Z mark II.
As far as the physically larger 150 MP sensor, maybe. As in maybe the lenses hold up to that. Maybe some redesign there for more DFA ones. They could do this. Maybe they will. But, they'd have to address the crop format unit first.
As far as timing goes, how many 50 MP chips did they buy in that last order and what is their production rate for the 645Z? I'm betting on two years worth. Unless they had the 645Y underway, which they might have because of the Fuji 100. But, there is that need for an NDA again to know. Which, I don't have. Just my crystal ball of experience.
Stan