I am very interested in this. However, full frame would be more ideal given the frameline indicated in the spec. 28/35/40/50 are the lenses that I have. If this is APSC then we are looking at view angle equivalent of 42/52/60/75 give or take a little which is still very usable. I use 35/50 the most and either format works in this sense.
My take on why they only published the pixel size but no sensor size is probably because the sensor is still being developed and the challenge of global shutter is read out speed. I wouldn't be surprised to see a full frame but low pixel count? if you want this to be an extension of the phone, the sensor has to outperform the phone to be worth while on top of form factor.
I look forward to the spec and price and reviews.