is almost confirmed in the latest chapter haise is dreaming with white kaneki
Or he has Kaneki's organs, same with the rest of his team. Consider that Kaneki had visions of Rize, but that didn't mean he was Rize.
But kaneki dreamt about rize because he met her, dated her a while and actually there while she made fun and tried to eat kaneki. Kaneki was traumatized by rize's attack, not too mention the effects of the ghoul organs taking effects on him. During that he almost totally lost his mind because he's not sure about was happening but he had a hunch on what's going and how it could happen. But he couldn't tell anyone about because he'll get killed or kill someone
IF kaneki died at the moment arima stabbed him then sasaki never had the chance to meet kaneki. So the chances of sasaki dreaming of kaneki due to organ or blood transfusion is highly unlikely. And if sasaki was only made by the CCG then he would have spoon fed all the information he needed and unlikely to go mad and go to a spree that might trigger a memory from kaneki's 'organs' ( but IF some part of kaneki's brain or eyes was included in surgery it can be very plausible) but sasaki going on a spree under CCG is unlikely.
But hey any thing's possible I just wish for an explanation for kaneki's being and hide being alive
Haise Sasaki isn't Ken Kaneki.
Kaneki is very handsome than Haise :)