I'd also like it very much if the M11 came with a 24-megapixel chip.
But it is also a fact that with other variables kept the same, having more megapixels doesn't exactly hurt the image. This subject was thoroughly explored by reviewers when the 40-megapixel M10R came out.
If the camera indeed has an interesting raw downsizing mechanism, that'll be interesting to see if it works in practice. In my opinion if the feature can produce for example a 30 megapixel raw file that's visually indistinguishable from a 60-resized-down-to-30-using-good-algorithms-file, then it's a useful feature and I for one would use it.
It is easier to do a 4:1 reduction, each combine 8x8 Bayer pattern pixels into the 2x2- just add and store as 16-bit values/pixel. Interpolating 60MPixels to 20MPixels- would be a pain.
I haven't studied the subject too much but don't videographers complain when their cameras do pixel binning, introducing moiré and softness and whatnot?
Then again, mobile phones these days advertise up to 108 megapixel sensors, they obviously do plenty of downscaling of varying sorts I assume.