Ah, da hatte ich wohl noch den zweiten Bericht im Hinterkopf. Der
Metabones soll aber auch so gut funktionieren:

According to DPReview Administrators (who just wrote a hands-on Preview with Sony a7R II article), the new announced Sony Alpha a7R II ’s on-sensor phase-detection AF works “very well” with Canon EF lenses via Metabones Adapter.


From dpreview:
By Rishi Sanyal
“Agreed. PDAF works with Canon lenses via Metabones adapter, and A-mount lenses via the LA-E3. We’re checking to see if you actually get the full AF coverage with subject tracking, but for now, consider our minds blown. ”
By Barney Britton
“It works, and it works very well. And yes, I just saw it demonstrated.”