Yep, the EF-M version is actually one of the heaviest models they make for this lens, so, its definitely an adapter built in.
Obviously for Canon EF, the 50mm from Canon is cheaper and has auto-focus. And there are endless 50mm options for mirrorless cameras that make it silly to get this for those, unless it somehow has world-stopping sharpness or bokeh.
They pretty much are making cine lenses for people that want a set with focus grips. Makes sense, especially since the other cine options are 10x the price.