First, let’s look at some old LeicaRumors blog posts:
Leica has now confirmed to be working on a new “hybrid” mirrorless large format sensor (not sure what that exactly means):
“Leica S3: the German firm abandons its 64 Mpx SLR to turn to the medium format hybrid
On the sidelines of the celebrations of the 50th anniversary of its factory in Portugal, Leica announced that it would stop production of its S3 medium format SLR . All this in an effort to make room for a future large-sensor hybrid . An intriguing device in more than one way.
A little over 3 years later, Leica finally announced that production of the S3 has ceased. But fans of medium format Leica can rest assured, the Wetzlar company is now working on a hybrid equipped with a large format sensor.” (Phototrend)