Truth be told, the CL is a great camera, but it has the limitation of a cropped sensor.
The SL and SL2 are also great cameras, but they are mucho big and heavy. Not so many willing to glass-up with APO lenses. Mucho expensive.
The Leica "Q" and Q2 are full frame, but fixed lens. Both also a great cameras. Some people would love a Q with a 35mm FOV or a 50mm FOV. AF is a bonus.
So what could a M-EVF be? Perhaps a merging of three current cameras. M-sized, M-mount, EVF and rear display of a SL2, full frame with the elegant controls of the M10/CL, and possible addition eventually overtime of AF M-lenses one day.
Not sure it would get IBIS or 47 MP, otherwise why buy a SL2 other than to optimize APO glass.
Cal