Seems reasonable to me to assume that PDAF that is sensor based and found in more recent Canon DSLRs would also be found in any newer EOS-M - with perhaps even better algorithms behind it to deliver better AF than prior
the 7D Mark II has far more tweaking available to it for PDAF settings, so it's obvious that canon is still actively augmenting it. it's not the same as the 70D.
From the 7D Mark II literature:
New DAF features include user-selectable adjustments for Movie Servo AF Speed and Movie Servo AF Tracking Sensitivity. Additionally, overall focusing speed, face detection performance, and performance in low light and with low-contrast subjects have been improved over previous Canon models
I would imagine DiGiC 6's increased performance has alot to do with it.
also I believe when ML was doing the EOS-M breakdown, they found out that the liveview framerate was cranked up more than the normal DSLR one (i recall one statement as such from them on that) - and canon even admitted that with the original EOS-M firmware version 2.0 they redid algorithms.
there's nothing stopping canon from cranking up the fps on liveview (which makes contrast detect work quicker) and also continually improving PDAF algorithms.
They didn't do it for their flagship APS-C camera though, so again, why will they do it for a much cheaper M?
Seriously, the new M is going to be a mirrorless beater because it will have some movie AF tweets?
Hoping to be pleasantly surprised, but not expecting anything...