How does it focus without a rangefinder?
I have a beautiful Leica MD-2 that has no rangefinder or viewfinder - so, your statement that the anticipated M camera is the first M Leica without a rangefinder is not factual. The MD-2 is not the only model without viewfinder or rangefinder. I have it dedicated for street photography and use 15mm and 24mm Voigtländer non-coupled lenses with shoe mounted finders - oh yeah, also an Elmarit-M 28mm. It is like silk and silent.
Hyperfocal scale focus of course but at f/8 everything is in focus.