We do know that the Hy6 traded wide angles for a rotating back so that is nothing new in the positive direction, and the H system is a closed architecture nothing positive as well.
The 645 AF/AFD is already much better than the other available systems that only a small increment will make it even more so ... but then again, this is only one more bias opinion and speculation while we wait for the information
"H system is a closed architecture nothing positive"?
On the contrary, there many positive aspects to the "closed system architecture". More critical focus due to focus adapation and known placement of the sensor in relation to the camera, automatic correction of lens distortion, apochromatic aberrations, and vignetting, etc. My customers find these aspects extremely positive.
There is much positive news on the Hy6 as well. It accepts digitally adjusted Schneider AF lenses, employs a fast and responsive AF system, provides ergonomically advanced camera controls, and will continue to benefit from digital/camera integration into the future.
While I think the Mamiya AFD is a fine camera - I am a Mamiya reseller, and the Aptus 65 with free Mamiya AFDII is a great value right now - let's be honest, it's always been the "value" choice, not the preferred solution. While H2 cameras were in production, they outsold Mamiya cameras by more than 3 to 1 in the US, despite the higher price.