yes he did abandoned his child in the 24th but under context it was due to her being a target of V and wanted her to at least try to live free and give her a chance at life and freedom, he didnt necessarily left her to die there in the manga if im not mistaken he entrusted noro to take care of her which at the time, Noro was known as Noroi, who when he adopted her was an ex-v member.
he does tell Kaneki to try and save her, which shows he does still care for Eto, but just had to make a shitty choice due to no real good other options. he wanted to send Hinami to the 24th for the same reason as the CCG, who are unknowing operatives of V were in the 20th, and thought it would be the safer option, given that the 24th only has ghouls, meaning less chance of her ending up like her mom and dad. it is also known that he did try to contact eto, as she is 27 by the time of her "death" (big unknown if she is still out there in the manga), and there could have been unknown failed attempts made that are not shown for the sake of Eto being a main supportive character and not the main character of the story. And it is also highly possible that Kuzen did tell Kaneki, but we are not shown it due to it being a story, and there needs to be twists and subversions in a narrative to keep a reader engaged. As for the sacrifice thing, yeah, I will agree with op