I'm sure we have seem a 120mpx APS-H sensor before:
http://www.dpreview.com/articles/2549658574/cp-2015-canon-shows-off-prototype-120mp-cmos-sensor
The bit that caught my attention was:
http://www.dpreview.com/articles/2549658574/cp-2015-canon-shows-off-prototype-120mp-cmos-sensor
The bit that caught my attention was:
... help in their sensor's noise performance (possibly by integrating on-chip ADCs).