a 18 MP sensor is unlikely i think.
why should canon produce a new 18 MP sensor with dual pixel AF when they have already such a 20 MP sensor? makes not much sense.
Where did you get that this has dual pixel AF?
• APS-C 18MP sensor
• Hybrid CMOS AF II
Hybrid CMOS II ≠ DPAF. The sensor described above is the one in the 700D/T5i and 100D/SL1 (which is different than the T4i/650D and EOS M sensor - those have the original Hybrid CMOS which is basically only the center of the frame, whereas Hybrid CMOS II covers a much larger area of the frame).
Some time back, the rumor was for two new models in the M lineup - a 'low end' one that is a little smaller than the current M and targeted at 'consumers', and a 'high end' one incorporating DPAF and coming a bit later.
This rumor sounds like the former, particularly with the smartphone integration stuff.